• Title/Summary/Keyword: 토궤적

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A Study on Adaptive Design of Experiment for Sequential Free-fall Experiments in a Shock Tunnel (충격파 풍동에서의 연속적 자유낙하 실험에 대한 적응적 실험 계획법 적용 연구)

  • Choi, Uihwan;Lee, Juseong;Song, Hakyoon;Sung, Taehyun;Park, Gisu;Ahn, Jaemyung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.10
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    • pp.798-805
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    • 2018
  • This study introduces an adaptive design of experiment (DoE) approach for the hypersonic shock-tunnel testing. A series of experiments are conducted to model the pitch moment coefficient of a cone as the function of the angle of attack and the pitch rate. An algorithm to construct the trajectory of the test model from the images obtained by the high-speed camera is developed to effectively analyze multiple time series experimental data. An adaptive DoE procedure to determine the experimental point based on the analysis results of the past experiments using the algorithm is proposed.

LIQUID APOGEE ENGINE BURN PLANS FOR THE KOREASAT-3 (액체추진제를 사용한 무궁화위성 3호의 정지궤도 진입 시뮬레이션)

  • 윤재철;최규홍;김두환;김방엽;김은규
    • Journal of Astronomy and Space Sciences
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    • v.15 no.2
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    • pp.427-436
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    • 1998
  • The apogee manoeuvre of $KOREASAT-1{cdot}2{cdot}3$ is basic elliptical orbit transfer converting orbit plane. The KOREASAT-3 is planed for multi-burn manoeuvres using the liquid apogee engine while the $KOREASAT-1{cdot}2$ used the apogee kick motor that executes a single burn in the apogee of transfer orbit using the solid propellant. This study analyzed the multi-burn manoeuvres using the liquid apogee engine and the propellant control method and developed the simulation tools. For the purpose of precise simulation, We designed tools in the basic of orbit propagation software, COWELL5, that was developed by members of Center for Astrodynamics in Yonsei university and the results can be displayed in 3-D graphic of $STK/VO^{TM}$.

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Analysis for Traffic Accidents against Car-Pedestrian on Simulation (시뮬레이션을 통한 차대 보행자의 교통사고 분석)

  • Chae, Hee-Hong;Lim, Jong-Han
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.115-121
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    • 2012
  • In spite of serious injuries caused by traffic accidents of car-pedestrian, the dispute is constantly occurring and economic losses and mental suffering is escalating since the cause of accidents is not scientifically identified. This study reviewed vehicle dynamics, driving dynamics, collision dynamics, traffic and road engineering for traffic accidents analysis based on traffic accidents related physically objective evidence and analysed the cause of accidents by getting results which applied vehicle initial collision velocity before collision, processing trajectory, collision stance, vehicle velocity before & after collision and parameter by using PC-Crash program. I found that skid mark and collision velocity of car-pedestrian had the error of 11.2%, 2,27% compared to theoretical values.

A Study on Safety Assessment for Ship Sailing under Electric Power Cable (해월(海越)송전선 하부의 선박 통항 안전성 평가에 관한 연구)

  • Kim, Hyun-Jong;Hong, Tae-Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.13 no.1 s.28
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    • pp.55-60
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    • 2007
  • Many electric power cables span the sea in Korean archipelago. Lots of shipping routes were established between the islands in the same area and ships frequently sail under the cable which cross the seas. Sometimes electric power cables were accidently broken by sailing ships and catastrophic damage of island industry followed thereby. If navigators have detailed knowledge about the height of electric power cable, the ship's sailing condition will be greatly improved. But at the present time, navigators have limited data about the electric power cable. Those are the horizontal distance between pylons, the height of pylons and minimum height of electric power cable. This study introduced the calculating methodology to find out the height of cable at any position between pylons. The ship's tracks were recorded and traffic safety was assessed by statistical method in relation to cable height.

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A Study on the Combined custom furniture Design for Single Person Households (Focused on the art furniture table) (1인가구를 위한 조합형 커스텀 가구디자인 연구 (아트퍼니처 테이블을 중심으로))

  • Hwang, Sun-Wook
    • Journal of Digital Convergence
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    • v.16 no.7
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    • pp.393-400
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    • 2018
  • I would like to design a customized furniture for one-person households that have emerged as mainstream in modern society. In particular, I focused on the tendency of generations to improve the quality of life, and wanted to design the aesthetic furniture close to art furniture. To this end, I look at art furniture in domestic and overseas furniture. and present the concept of combined custom design based on current trends. The combined custom design differs from the existing one by creating separate designs for each part and fusing them to enable more diverse and aggressive molding. This is in harmony with the active tendency of one-person households who shows a lot of interest in the quality of life. Especially, it is suitable for small quantity production of various kinds, so it can be produced in the existing craft workshop system, and the two tables can confirm the possibility of the morphological concept according to actual combined custom design.

Female Middle-Aged Householders' Experiences in Preparation for Old Age: With Focus on Career Female Householders (중년 여성가구주의 노후준비 경험: 직업이 있는 여성가구주를 중심으로)

Analysis of vehicle central line invasion accidents using simulation (시뮬레이션을 이용한 차량의 중앙선 침범 사고 해석)

  • Han, Chang-Pyoung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.507-513
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    • 2021
  • This study examined the final stop position and posture of both vehicles, the damaged part of the vehicle, the road surface, the specifications of the vehicle, and the angle of impact, centering on the case of a collision in which no surface trace was found. As a result of the simulation, the impact velocity of an SM5 and Lexus was 131 km/h and 74 km/h, respectively, and the impact angle of the SM5 and Lexus was 0.91° and -161.07°, respectively. The cause of the accident was that the SM5 passed through the intersection exceeding the maximum speed limit of 61 km/h and entered the Lexus' left turn lane. Lexus collided during the evacuation to avoid the collision. The collision trajectory error rate of the simulation was approximately 1.4%. Of the subjective experience of accident investigators, the collision dynamics and vehicle engineering aspects and simulations were actively utilized to provide close-to-fact cause identification.

A. Artaud or the Prisoner of Language (앙토냉 아르토 혹은 언어의 수형자)

  • Park, Hyung-Sub
    • Cross-Cultural Studies
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    • v.45
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    • pp.219-243
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    • 2016
  • The life of Antonin Artaud exactly reproduces a very cruel drama. He lived in constant anguish and suffered from severe mental pain. This research will trace his thoughts in his writings while he was a prisoner of language. Artaud was a poet filled with anxiety about language, things, being, and thought. Whenever he tried to explain the mystery of being by means of mundane language, he experienced psychological agony. His poetic thoughts began to break down, because of his identity loss. Nevertheless, he was destined to grasp the world through language. Artaud had suffered from mental illness during his youth. His mental illness was associated with his difficulty in creating poetry. In this research, the letter, Correspondance avec Jacques $Rivi{\grave{e}}re$, is analyzed. The poet refers to "the collapse of the spirit's core, and the erosion of the fundamental thought that slips away" to convey his linguistic incompetence. Hereafter, he constantly demonstrated anxious mental symptoms. Even though he became mentally deranged, he maintained his consciousness, as is apparent in his writings. Also, his spiritual belief is reflected in his mental uneasiness. While he was traveling through the Tarahumaras area in Mexico, he was obsessed with its primitive belief in the Peyote rituals, and he immersed himself in performing them. His unchristian belief was the product of his mystical personality. Until his last breath, he did not give up writing. Artaud's mental derangement does not mean lunacy, but if one insists in calling it so, that is a metaphor. His derangement comes from his refusal to accept his limitations and from his aspiring to regard his body in the same light as his intellectual perceptions. His intellect could manifest more easily when his mind was elevated to the extreme. Artaud's lunacy is no different from that of a profound philosopher. The lives of poets who suffer from mental derangement are more poetic than the lives of those who do not. Artaud's atypical emotions provide a way of to measure our own limitations, helplessness, and resignation. His scream is nonsegmental but different from that of a mental patient. That difference is why people are interested in his works and wish to delve into his writings.

The Roles of Wind Shadow Aspect Ratio upon the Behaviors of Transverse Dunes : A Dynamics Analysis on the Behavior Space (바람그늘의 기울기가 횡사구의 지형발달에서 담당하는 역할 -거동 공간상의 동역학적 분석을 중심으로-)

  • RHEW, Hosahng
    • Journal of the Korean association of regional geographers
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    • v.22 no.4
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    • pp.887-911
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    • 2016
  • The empirical law that transverse dunes migrate inversely with their heights leads logically to the prediction that multiple dune ridges will converse to a single huge dune by merging. This contradicts the existence of the steady state dune fields on the Earth. The recent studies have emphasized dune collisions as a key mechanism to the stability of dunefield. The roles of wind shadow aspect ratio, however, have yet to be fully explored. This research aims to investigate the potential roles of wind shadow aspect ratio in the dynamical behaviors of transverse dune field. The simplified model is established for this, based upon allometric properties of transverse dunes, wind speedup on the stoss slope and sand trapping efficiency. The derived governing equations can be transformed to the zoning criteria and vector field for dune evolution. The dynamics analysis indicates that wind shadow aspect ratios do not produce convergent areas on the behavior space; rather, they just act as one of the factors that affect the trajectories of dune evolution. Though the model cannot represent the stability of dune field, but seem to produce a reasonable exponent for dune spacing-height relations.

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Enhancement for Performance of Monopulse and Target Tracking for Communication Signal Tracking (통신신호 추적을 위한 모노펄스 및 추적성능 향상 방안)

  • Kil, Hyun Joo;Lee, Young Jin;Kim, Jae Sin;Lee, Eun Seok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.5
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    • pp.35-43
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    • 2014
  • In this paper, we propose a performance enhancement method of the target tracking system for communication signal using the monopulse and the ${\alpha}{\beta}$ filter to keep the connection of the communication system between the airplane and the ground. We suggest the minimum distance measurement method for tracking error angle of the monopulse signal instead of the generally used method of MR(Monopulse Ratio) curve, and the ${\alpha}{\beta}$ filter with variable gain for enhancement of the tracking accuracy and the probability of re-tracking the monopulse signal under the disconnection of link. We show the performance enhancement of the proposed method of monopulse system using the measured MR Curve results of the prototype system. And also, the comparison of simulation results between the ${\alpha}{\beta}$ filter with variable gain and the ${\alpha}{\beta}$ filter with fixed gain shows the performance enhancement of the proposed ${\alpha}{\beta}$ filter. Using the proposed methods, we expect the enhanced performance of the existing target tracking system for communication signal only by changing the algorithm without hardware changes.