• 제목/요약/키워드: G-Force

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G-induced Loss of Consciousness(G-LOC) 예측을 위한 신체 부위별 Electromyogram(EMG) 신호 분석 (Analysis on Electromyogram(EMG) Signals by Body Parts for G-induced Loss of Consciousness(G-LOC) Prediction)

  • 김성호;김동수;조태환;이용균;최부용
    • 한국군사과학기술학회지
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    • 제20권1호
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    • pp.119-128
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    • 2017

  • G-induced Loss of Consciousness(G-LOC) can be predicted by measuring Electromyogram(EMG) signals. Existing studies have mainly focused on specific body parts and lacked of consideration with quantitative EMG indices. The purpose of this study is to analyze the indices of EMG signals by human body parts for monitoring G-LOC condition. The data of seven EMG features such as Root Mean Square(RMS), Integrated Absolute Value(IAV), and Mean Absolute Value(MAV) for reflecting muscle contraction and Slope Sign Changes(SSC), Waveform Length (WL), Zero Crossing(ZC), and Median Frequency(MF) for representing muscle contraction and fatigue was retrieved from high G-training on a human centrifuge simulator. A total of 19 trainees out of 47 trainees of the Korean Air Force fell into G-LOC condition during the training in attaching EMG sensor to three body parts(neck, abdomen, calf). IAV, MAV, WL, and ZC under condition after G-LOC were decreased by 17 %, 17 %, 18 %, and 4 % comparing to those under condition before G-LOC respectively. Also, RMS, IAV, MAV, and WL in neck part under condition after G-LOC were higher than those under condition before G-LOC; while, those in abdomen and calf part lower. This study suggest that measurement of IAV and WL by attaching EMG sensor to calf part may be optimal for predicting G-LOC.

  • https://doi.org/10.9766/KIMST.2017.20.1.119 인용 PDF KSCI

환상형 클래스프의 유지력에 관한 연구 (A STUDY ON THE RETENTIVE FORCE OF CIRCUMFERENTIAL CLASP)

  • 이재순;방몽숙
    • 대한치과보철학회지
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    • 제36권5호
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    • pp.669-682
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    • 1998

  • The purpose of this study was to compare the retentive force of cast half round circumferential clasps, cast round circumferential clasps and wrought wire clasps on three different depths of undercut(10G,20G.30G), and to determine the proper amount of undercut for cast round circumferential clasp. Three different lower second premolar crowns were cast and each of clasp was made. Each of clasp affixed to the different types of clasp. Their retentive forces were measured with universal testing machine. The results were as follows : 1. When the depth of undercut was same, the greatest retentive force was exerted by cast half round circumferential clasp, followed by cast round - 33 - circumferential clasp and wrought wire clasp. 2. The degree of variation amount of retentive force according to depth of undercut was greatest for cast round circumferential clasp. 3. Not only elastic deformation but also permanent deformation of the retentive arm was observed after insertion and removal of the clasp. The results of this study show that the retentive force of cast round circumferential clasp falls between those of cast half round circumferential clasp and wrought wire clasp, and suggest that a 20G undercut is suitable for ensuring an appropriate degree of the retentive force.

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