• 제목/요약/키워드: Thrust Force

검색결과 681건 처리시간 0.026초

익수사고자에 대한 효과적인 응급처치 방법 (An effective emergency care of a person from water submersion)

  • 오용교;박형선
    • 한국응급구조학회지
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    • 제2권1호
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    • pp.26-35
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    • 1998
  • This study was to exhibit the effective emergency care method for the drowning and non-drowning who are reached two-thousand peoples every year in our country. For investigate the effective emergency care, this study was discussed as follows ; Pathophysiology of the water submersion, Fresh-water & sea-water drowning, Factors affecting survival, and Prehospital management. The conclusions from this study were summarized as follows; 1. Remove the patient from the water. If you suspect neck or spinal injuries, Always support the head and neck level with the back and, begin rescue breathing. 2. Maintain the airway and support ventilation in the water use the jaw-thrust technique to avoid farther injury to the neck or spine. We might encounter more resistance to ventilations than you expect because of water in the airway. Once you have determined that there are no foreign objects in the airway, apply ventilations with more force; adjust ventilations until you see the patient's chest rise and fall but not until you see gastric distention. Do not attempt to remove water from the patient's lungs or stomach. 3. If there is no pulse, begin CPR. 4. Administer high-flow supplemental oxygen; suction as needed. 5. Once the patient is breathing and has a pulse, assess for hemorrhage; control any serious bleeding that you find. 6. Cover the patient to conserve body heat, Handle the patient very gently, and, Transport the patient as quickly as possible to Emergency Department, Continuing resuscitative measures during transport. If the patient have the hypothermia, follow hypothermia management.

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평엔드밀링 공정에서 절삭속도 및 이송속도가 측벽의 축방향 형상에 미치는 영향 (Effects of Cutting Speed and Feed Rate on Axial Shape in Side Walls Generated by Flat End-milling Process)

  • 김강
    • 대한기계학회논문집A
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    • 제41권5호
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    • pp.391-399
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    • 2017
  • 절삭속도 및 이송속도가 평엔드밀로 하향절삭 가공된 측벽 형상에 미치는 영향을 실험을 통하여 알아보고자 한다. 실험은 절삭속도 및 공구 직경, 절삭날 당 이송거리를 변수로 하여 수행하며, 실험 결과로서 배분력과 축방향 형상을 측정한다. 연구 결과, 이송속도를 절삭속도로 나눈 값에 비례하는 날 당 이송거리가 작을수록 축방향 형상정밀도가 높아지는 것이 확인되었다. 아울러, 축방향 형상은 서로 다른 기울기를 갖는 두 직선이 특이점에서 만나는 형태로 단순화 할 수 있다. 그러므로 운전 중 작업자에 의한 형상정밀도의 추정 및 날 당 이송거리 조정에 의한 개선이 용이할 것으로 판단된다.

대형 멀티 전자기 가진 시스템의 구성 및 설계 (Configuration and Design of the Large Multi-Electromagnetic Shaking System)

  • 우성현;김홍배;문상무;김영기;임종민
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.618-622
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    • 2004
  • The vibration test system of SITC(Satellite Integration and Test Center) at KARI(Korea Aerospace Research Institute) has been used successfully for the environmental tests of a majority of korean space programs, such as KOMPSAT, Koreasat KITSAT, STSAT and KSR program since 1996. To meet the recent needs of large size test facility available for the vibrational tests of the huge launch vehicles and tole-communication satellites which will be developed in the near future, KARI undertook to construct the large size multi-electromagnetic shaking system with 3 $\times$ 3m head expander system. The new system will consist of three electromagnetic shakers which has 160 kN thrust force individually, and be able te sustain up to 8 tons test load and 300 kNm overturing moment. And to avoid the tremendous cost and effort to furnish the seismic block with large size and weight, it will adopt a Lin-E-Air type configuration with which the seismic block is less severe than a Solid-Truninon type. In addition, to fulfill the strong requirement of high overturning moment the additional guidance system including a central bearing system on a central support and several pad bearings around the head expander body is now considered. This paper describes the configuration and the design parameters of the multi-shaking system which is under development by KARI's engineers.

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석문일월무예 음양보법의 숙련성에 따른 보행 패턴의 하지 운동학 및 운동역학적 특성 (A Study of Motor Expertise about Kinematic and Kinetic Characteristics of Lower Extremity in the Seokmun Ilwol Martial Art Yin-yang Bo Gait Pattern)

  • 박복희;김기형
    • 한국운동역학회지
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    • 제24권3호
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    • pp.239-248
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    • 2014
  • The purpose of this study was to quantify kinematic and kinetic characteristics of Yin-yang Bo gait according to their motor expertise, one of the Seokmun Ilwol martial art gait patterns. Yin-yang Bo gait pattern shows initial forefoot contact instead of heel contact, and increased time of stance phase time, internal-external rotation of ankle-knee-hip joints and pelvic. It aims to produce and store the more energy through continuous homeostasis of center of gravity (COG) and performance of stretch-shortening cycle. Some of these characteristics also were similar to the gait modification strategies for reducing knee adduction moment such as toe-out progression, medial thrust, internal rotation of hip joint. To identify the characteristics, four factors of expert Yin-yang Bo gait performance group were compared to that of none expert group; 1) angles of COG displacement and rotation 2) distal joint pre-rotation in internal-external rotation of ankle-knee-hip joints and pelvic, 3) invariability pelvic potential and pelvic segment total energy 4) knee abduction moment. Six healthy(three male) subjects participated in the experiment to perform Yin-yang gait pattern. Three-dimensional and force plate data were collected. Kinematic and kinetic data were compared between two groups using t-tests. Results showed that 1) the peak point of COG internal rotation angle was reduced in expert group, 2) kneeexternal and hip joint -internal and pelvic rotation angle peak frames were more near points in expert group.

엔드밀링 공정의 형상창성기구에 의하여 절삭면적이 측벽 진직도 특성에 미치는 영향 (Effects of Cutting Area on Straightness Characteristics in Side Walls Caused by Form Generation Mechanism in End-Milling Process)

  • 김강
    • 대한기계학회논문집A
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    • 제37권10호
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    • pp.1269-1278
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    • 2013
  • 엔드밀링 공정은 형상창성기구의 특성 상, 절삭면적의 주기적인 변화를 피할 수 없다. 그러므로, 본 연구에서는, 가공 중 절삭날과 공작물 사이의 간섭영역에 해당하는 절삭면적의 모델을 확립하여, 가공면 형상 특성과 절삭면적의 관계를 규명하고자 한다. 대상 가공면은 측벽을 선정하였으며, 형상 특성은 축 방향 진직도를 선택하였다. 절삭면적 및 축방향 진직도에 영향을 미치는 특이점 추정 모델의 타당성은 반경 방향 및 축 방향 절삭깊이를 변화시키며 엔드밀링 가공을 수행하여 검증하였다. 연구 결과, 배분력이 음의 값을 갖지 않는 안정적인 엔드밀링 가공의 경우, 상향절삭은 절삭면적이 증가했다. 일정해지는 영역에서, 하향절삭은 절삭면적이 일정했다 감소하는 영역에서 가공면을 창성하며, 영역이 변화될 때 가공면에 특이점이 발생하는 것이 확인되었다.

대형 유조선의 저항 및 추진성능에 대한 축척효과의 수치적 연구 (Computational Study of the Scale Effect on Resistance and Propulsion Performance of VLCC)

  • 최정은;김정훈;이홍기
    • 대한조선학회논문집
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    • 제48권3호
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    • pp.222-232
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    • 2011
  • This article examines the scale effect of the flow characteristics, resistance and propulsion performance on a 317k VLCC. The turbulent flows around a ship in both towing and self-propulsion conditions are analyzed by solving the Reynolds-averaged Navier-Stokes equation together with the application of Reynolds stress turbulence model. The computations are carried out in both model- and full-scale. A double-body model is applied for the treatment of free surface. An asymmetric body-force propeller is used. The speed performances including resistance and propulsion factors are obtained from two kinds of methods. One is to analyze the computational results in model scale through the revised ITTC' 78 method. The other is directly to analyze the computational results in full scale. Based on the computational predictions, scale effects of the resistance and the self-propulsion factors including form factor, thrust deduction fraction, effective wake fraction and various efficiencies are investigated. Scale effects of the streamline pattern, hull pressure and local flow characteristics including x-constant sections, propeller and center plane, and transom region are also investigated. This study presents a useful tool to hull-form and propeller designers, and towing-tank experimenters to take the scale effect into consideration.

매트랩을 기반으로 한 U자형 금속 벨로우즈 설계소프트웨어 개발 (Development of U-shaped Metal Bellows design software based on MATLAB)

  • 장봉춘;김성철
    • 한국산학기술학회논문지
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    • 제16권4호
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    • pp.2379-2384
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    • 2015
  • 벨로우즈 제품은 플랜트 엔지니어링, 조선, 석유 화학의 분야에서 중요한 부분이다. 안전성 및 내구성을 위해 벨로우즈를 설계 할 때 많은 요인들을 고려할 필요가 있다. 본 연구에서는 EJMA 9th Edition 설명서를 기초로 하여 U자형 금속 벨로우즈 전용 설계 소프트웨어를 개발했다. 이 GUI 소프트웨어는 매트랩 소프트웨어를 사용하여 개발되었으며, 비보강 단일 벨로우즈, 비보강 복식 벨로우즈, 보강 단일 벨로우즈, 보강 복식 벨로우즈를 설계할 수 있다. 이 소프트웨어를 검증하기 위해 이미 검증된 벨로우즈 모델을 설계하고 두께를 변화시키면서 벨로우즈의 거동을 고찰하였다. 두께가 증가함에 따라 스프링상수, 추력, 응력은 증가하고 피로수명은 감소함을 알 수 있었다. 이 소프트웨어는 설계 엔지니어의 시간과 노력을 절약해 줄 것이다.

대통합 언어이론을 향하여 (Toward an Integrated Theory of Language)

  • 문경환
    • 인문언어
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    • 제1권1호
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    • pp.33-63
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    • 2001
  • This article does not deal with a theory or theories in the usual sense of the term but rather harks back to its etymological source, theorein ' to look at.' The phrase 'theory of language' thus purports a 'view of language' and does not carry the force of scientific explication of language. In fact, the word ' scientific' or 'science' per se originates from scire 'to know' and is here to be considered not so much in regard to some kind of positivistic methodology as a form of knowledge. If this exposition sounds unduly ingenious, that is because one is caught up in all kinds of presuppositions about the words under consideration. Sometimes, when we come to grips with an issue that strikes our mind as truly important, our language, by the light of which we hope to proceed safely, plays the will-o'-the-wisp instead and leaves us in the middle of a murky maze, twisting what was at first blush a mere cinch into a Gordian knot. On such occasions, etymology comes along the way and sends us back to itself as its own principle: Resort to etymos logos 'original, true word'! The main thrust of the present study is that alongside the quantitative, positivistic thought there is another equally valuable mode of qualitative and humanistic thinking that makes a whole gamut of new and concrete investigations possible, that an integrated theory of language is Possible by way of a happy amalgamation of diversified, humanistic views of language. With this idea as the leitmotif we explore two models of theory which typically set themselves up for a 'scientific' approach to language: analytic philosophy that delves into what it calls logical simples, and contemporary linguistics that stubbornly teeters around some formal rigor or other. It is argued that they are both characterized by a looking away from the fluid, ill-definable aspects of language, giving a preference to segments and isolated facts as a means to avoid those larger wholes and totalities which if they had to be seen would in the long run lead to an uncomfortable state of mind. Language, in the final analysis, is a Protean entity: so capricious and multifarious, and yet so noetic and prophetic, that we should catch sight of its picturesque images in their entirety to give form to an integrated theory of language.

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초음속 이젝터의 압력회복에 관한 연구 (Pressure Recovery in a supersonic ejector of a high altitude testing chamber)

  • 조지;공창덕
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.833-837
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    • 2010
  • 본 연구는 최소 압력 모사로 엔진 배기가스를 배출시키기 위한 최적 이젝터 크기를 결정하기 위한 것을 목적으로 한다. 실험 챔버로 유입되는 2차 냉각 공기는 유량제어 밸브들과 진공펌프가 장착된 배출구를 통해 엔진배기가스는 분리되어 배출된다. 기존 고도시험 장치와 달리, 본 연구에 제안한 형상은 기존 이젝터의 압력 회복을 개선한 좀 더 작은 포획 면적을 가진 배기 이젝트를 사용하면 가스에 스텔링 챔버로 부터 20% 냉각 공기를 부가하여 배출시키도록 크기가 정해진다. 제안된 형상은 벨마우스 이젝터와 엔진배기 출구의 면적비가 이론적으로 약 1.2를 갖는다. 제안된 형상의 혼합 공기 모사결과에 따르면 큰 에너지는 기존 시스템 비해 좀 더 개선된 압력 회복과 감소된 전력 소모를 같음을 확인하였다.

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선박항법기기 화면의 배치에 관한 연구 (A Study of Contents Arrangement in Conning Display)

  • 윤훈용;김경훈
    • 산업경영시스템학회지
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    • 제33권2호
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    • pp.154-161
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    • 2010
  • The conning display which is located in the ship bridge shows the various important information such as ship position, ship speed, track data, rate of turn, thruster rpm so on, and is one of the IBSs(Integrated Bridge Systems). In this study, the survey was conducted for ten officers to find the importance and using frequency of the information which were displayed in the conning display. The results showed that the information of drift speed, ship speed, wind direction and wind force, rate of turn, sea water depth, ship position, heading, thrust rpm, alarm, rudder command and angle got high scores and it meant that these information were very important and high frequency of use during the navigation. The optimized contents arrangement in conning display was suggested based on importance and using frequency of information. The experiment using eye-tracking system was conducted to compare the performance time and error rate of nine different scenarios for suggested arrangement display and three other existing displays. The results showed that the suggested arrangement was the best in performance time and error rate. The scenario concerning the direction and speed of wind showed faster performance time and lower error rate than other scenarios. The movement of subject's eye tended to search from the center and to avoid the comer, called 'the comer effect.' It is expected that the results of this study could help for the bridge staff to grasp the sailing information easily and to cope with the given situations promptly.