• 제목/요약/키워드: Internal/External flow

검색결과 239건 처리시간 0.025초

이중 리브를 가진 냉간 압출품의 내.외부 결함 방지를 위한 공정 설계 (Process Design to Prevent Internal & External Defects of Cold Extruded Products with Double Ribs)

  • 김동진;김병민
    • 소성∙가공
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    • 제8권6호
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    • pp.612-619
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    • 1999
  • Internal and external defects of an inner pulley for automobile air conditioner are investigated in this study. Inner pulley is a part of compressor clutch assembly of automobile air conditioner. In cold forging of inner pulley, the design requirement are to keep the same height of the inner rib and outer one and to make uniform distribution of hardness in the forged product. At the end of the forging of inner pulley, the piping defect as an external defect begins to form at the back center of the billet. The internal crack as an internal defect also occur at the adiabatic shear band which usually has maximum ductile fracture value. It is important to predict when the internal and external defects occur during the deformation process, in order to minimize the amount of discard that is generated. The finite element simulations are applied to analyze the defects. The validity of the computational results are examined by experiments. These computational results are in good agreement with the experimental ones.

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이동원(李東垣) 내외상변맥법(內外傷辨脈法)의 유래와 이론적 근거에 대한 고찰 (Study on the origin and theoretical foundation of I Dong-won(李東垣)'s pulse diagnosis distinguishing internal and external injuries(內外傷辨脈法))

  • 장우창
    • 대한한의학원전학회지
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    • 제20권2호
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    • pp.137-145
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    • 2007
  • Pulse diagnosis that distinguishes internal injury from external injury by comparing the left and right of the chon pulse was formed in the process of Naegyoung's pulsation theory of ST9 and LU9 being assimilated into diagnostic method by taking chon pulse. The founder of school of internal injury, I Dong-won, expanded the horizon for this method to be widely used in clinical practice by especially explaining the specific application and theoretical background. According to him, pulse at ST9 which means chon pulse at the left hand, is bigger than the chon pulse at the right hand, it reflects external injury. Bigger "entrance pulse", a chon pulse at the right hand means internal injury. The reason is the left side of the body is a path for Yanggi so it controls the exterior part and the right side of the body is a path for Eumgi to descend so it controls the interior part. Internal injury develops as the spleen and stomach get injured. If the spleen and stomach is damaged essence derived from food cannot ascend to the stomach and will flow back to the lower part. As a result, fire of Eum type formed at the lower part will shoot up to the upper part and manifests external injury-like exterior syndromes. In this case, evidence distinguishing between internal and external injury is the fact that right hand pulse is bigger than the left hand. The important reason for distinguishing between internal and external injury is because when treating external injury caused by excess syndrome, pathogenic Gi should be dispelled. However, treating internal injury cased by deficiency syndrome, requires promoting the primordial Gi.

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원형 및 타원형 노즐 내부유동과 외부유동의 상관관계 (Correlations of Internal Nozzle Flow in Circular and Elliptical Nozzles with External Flow)

  • 구건우;홍정구;박철우;이충원
    • 대한기계학회논문집B
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    • 제36권3호
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    • pp.325-333
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    • 2012
  • 원형 및 타원노즐의 내부유동과 외부유동의 상관관계를 알아보기 위해 실험적 연구가 수행되었다. 분사압력에 따라 유량, 분무각, 액적크기 등의 외부유동에 관해 관찰하였고, 노즐 내부유동의 유속 및 압력분포 등을 수치해석을 통해 정량적인 결과를 도출하였다. 외부유동의 경우, 동일한 압력조건하에서 타원형 노즐의 경우, 원형 노즐에서 나타나지 않는 표면분열의 분무특성을 관찰할 수 있었고, 수치해석을 통해 노즐 내부의 유동을 분석한 결과, 원형의 경우와는 달리 타원형 노즐의 단축에서 내부유동의 재부착이 노즐 벽면에서 발생되었다. 타원노즐 외부유동의 표면분열이 내부유동에 따른 결과라고 판단된다.

노즐 내부 유동 소음원에 의한 공력 소음의 정량적 분석 (A quantitative analysis of aerodynamic noise by sound sources from a nozzle inflow)

  • 이권기;정철웅;박경훈
    • 한국음향학회지
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    • 제41권6호
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    • pp.698-704
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    • 2022
  • 본 논문에서는 노즐 내부 유동의 소음원으로부터 발생되어 방사되는 공력 소음을 정량적으로 분석하였으며, 이를 외부 방사소음 결과와 비교하였다. 세가지 종류의 노즐 형상에 대해 내부 및 외부 유동을 정확히 예측하기 위해 고해상도 수치해석 기법인 비정상 압축성 대와류모사(Large Eddy Simulation, LES) 기법을 사용하였다. 와류소음원(Vortex Sound Source)을 통해 유동소음원을 확인하였으며, 이를 통해 노즐 내부 형상에서 주요 유동소음원의 분포를 확인하였다. 노즐 내부 유동의 와류소음원 레벨과 외부 방사 소음의 예측결과 및 측정결과와 비교하였으며, 이를 통해 정량적 분석을 검증하였다.

가스발생기용 스월 동축형 인젝터에서 내부 유동의 특성에 대한 실험적 연구 (Experimental Study on the Internal Flow Characteristics in a Swirl Coaxial Injector for Gas Generator)

  • 김성혁;윤정수;윤영빈
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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    • pp.29-33
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    • 2010
  • 본 연구는 Kerosene-LOx를 추진제로 하는 가스발생기용 스월 동축형 인젝터의 리세스 길이에 따른 내부 유동의 특성 파악을 목표로 하였다. 리세스 길이는 분무 안정성, 내부 LOx post 손상 등에 영향을 미치는 중요한 요소로 액막두께, 매니폴드 압력 측정 및 내부 유동 가시화를 통해 리세스의 영향을 분석하였다. 또한, 리세스 길이에 따른 내부 또는 외부 인젝터 각각의 분무특성도 살펴보았다.

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TCD를 이용한 말초성(末梢性) 구안괘사환자에 대(對)한 임상적(臨床的) 고찰(考察) (The Clinical Study on Bell's Palsy Patients with TCD Measurement)

  • 이병렬;안택원;이현
    • 대한약침학회지
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    • 제6권2호
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    • pp.91-104
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    • 2003
  • Objective : This study was carried to make out the connection between cerebral artery blood flow velocity and ischemic theory that presumed the cause of Bell's palsy. Method : We measured cerebral artery blood flow velocity each external carotid artery, internal carotid artery, common carotid artery, siphon, superficial temporal artery by TCD to 20 patients who diagnosed as facial nerve palsy from march 2001 to July 2001 and all objectives devided two groups as palsy side. A group is right side facial nerve palsy and B group is left facial nerve palsy. Results : 1. There is no effective change of blood flow in external carotid artery either A, B group. 2. There is no effective change of blood flow in internal carotid artery either A, B group. 3. There is no effective change of blood flow in common carotid artery either A, B group. 4. There is no effective change of blood flow in siphon artery either A, B group. 5. There is no effective change of blood flow in superficial temporal artery either A, B group.

위절제술환자의 건강통제위에 따른 상호목표설정 간호중재의 효과 (Effects of Nursing Intervention of Mutual Goal Setting on Gastrectomy Patients According to Health Locus of Control)

  • 장은희
    • 기본간호학회지
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    • 제5권1호
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    • pp.107-124
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    • 1998
  • Based on King's goal attainment theory, this research deals with applying nursing intervention of mutual goal settings to gastrectomy patients. It tests the effects of nursing intervention, according to the patients' health locus of control, suggested as external boundary criteria for the theory by employing a quasi-experimental design which consists of a pretest-posttest non-equivalent control and experimental groups. The subjects of this research were 62 gastrectomy patients hospitalized at Y medical center and the experimental and control groups consisted of 31 subjects. The experimental group received nursing intervention at the mutual goal setting of 5 times from the day before the surgery to the 5th day after the surgery, while the control group received only routine nursing care. Recovery indicators of both groups were measured and compared. Measurement variables included patients' characteristics, health locus of control, forced vital capacity, forced expiratory volume in one second, peak expiratory flow, bowel movement recovery, mobility recovery, level of pain, patients' stress and patients' satisfaction. Data were analyzed using SPSS statistical package and the hypotheses were tested by ANOVA and ANCOVA. Results of the analyses are summarized as follows : 1) Internal health locus of control had higher effects of the nursing intervention of mutual goal setting than external health locus of control on pulmonary ventilatory functions of forced vital capacity, forced expiratory volume in one second, and peak expiratory flow. 2) There was no statistically significant difference in the effects of nursing intervention of mutual goal setting on the bowel movement recovery between the internal and external health locus of control. 3) There was no statistically significant difference in the effects of nursing intervention of mutual goal setting on the mobility recovery between the internal and external health locus of control. 4) There was no statistically significant difference in the effects of nursing intervention of mutual goal setting on the level of pain between the internal and external health locus of control. 5) There was no statistically significant difference in the effects of nursing intervention of mutual goal setting on the level of stress between the internal and external health locus of control. 6) There was a statistically significant difference in the effects of nursing intervention of mutual goal setting on the level of satisfaction with provision of nursing information between the internal and external health locus of control, and there was no statistically significant difference in the effects of nursing intervention of mutual goal setting on the level of satisfaction with outcome of nursing between the internal and external locus of control. On the basis of the research results, the following are recommended : 1) Repeated research on responses to health locus of control is necessary. 2) Not only the effectiveness of nursing intervention in acute recovery periods, but also the long term effects are to be investigated. 3) The development of instruments is needed to accurately measure mutual goal setting regarding postoperative deep breath, coughing, early ambulation, etc. so that the relationship among the postoperative recovery indicators may be explored. 4) It is required that an instrument be developed to measure perception which facilitates goal attainment in the interactive setting between patients and nurses.

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제약회사의 현금흐름이 연구개발투자에 미치는 영향 -코스닥시장을 중심으로 (Effect of Cash flow on the R&D investment of Pharmaceutical Companies - focused on KOSDAQ market)

  • 이문재;최만규
    • 한국콘텐츠학회논문지
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    • 제15권8호
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    • pp.473-480
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    • 2015
  • 본 연구는 우리나라 코스닥 제약회사를 대상으로 내 외부금융이 연구개발투자(R&D)에 미치는 영향을 분석하였다. 실증분석을 위한 표본은 2009년부터 2013년까지 상장된 기업들 중 코스닥 제약회사를 대상으로 하였으며 사용된 전체 표본은 5개년 자료로써 212개 관측치를 가진 불균형패널자료이다. 본 연구에 사용된 주요 변수들 중 개별기업 별 재무자료는 상장회사 협의회의 TS-2000, 금융감독원 전자공시 시스템의 각 기업 사업보고서, NICE신용평가정보의 KISVALUE-III 등의 자료를 통해 직접 수집하였으며, 패널분석을 위해 STATA 12.0을 사용하였다. 연구결과, 첫째 내부금융(유동비율)은 연구개발투자에 긍정적인 영향을 미쳤다. 둘째, 외부금융(부채비율)은 연구개발투자에 부정적인 영향을 미쳤다. 본 연구는 자본시장에서 정보의 비대칭으로 인해 외부금융보다 내부금융이 더 선호됨을 알 수 있다. 즉, 제약기업의 연구개발투자 활성화를 위해 내부금융의 관리 및 정부의 정책적 지원이 필요함을 보여준다.

Bleed Air 냉각용 열교환기 개발 (Development of Heat Exchanger for Cooling Bleed Air)

  • 유경원;백낙곤;박봉교;김준태
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
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    • pp.427-430
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    • 2008
  • 본 연구에서는 엔진으로부터 나오는 고온 여압 공기를 냉각시키기 위한 열교환기 개발을 수행하였다. 장착 환경을 고려한 외부 유동 흐름 및 열교환기 내부의 유동과 열전달 특성에 대한 전산해석을 통해 열교환기의 형상 및 유로 설계를 수행하였으며 이를 검증하기 위해 사용 환경 모사 시험을 수행하여, 그 결과를 비교하였다.

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나선형 내부전극을 사용한 2중 원통형 오존발생기의 온도의존특성 (Temperature Dependence Characteristics of Double Cylindrical Type Ozonizer Using Spiral Type Internal Electrode)

  • 전병준;이상근;;이동헌;박원주;이광식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1999년도 하계학술대회 논문집 E
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    • pp.2004-2006
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    • 1999
  • In this paper, double Cylindrical type ozonizer has been designed and manufactured to improve ozone yield by cooling external electrode. The ozonizer equipped with three electrodes ( central, internal and external electrodes ). Discharge and ozone characteristics are described in this paper by varying the flow rate( Q ) of oxygen supplied gas, temperature of cooling gas and supplied voltage.

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