• 제목/요약/키워드: Air Force

검색결과 1,948건 처리시간 0.035초

$LiZnBO_3$ : 결정구조 ($LiZnBO_3$: Crystal Structure)

  • 장기석
    • 대한화학회지
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    • 제45권3호
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    • pp.251-255
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    • 2001
  • LiZnBO3 화합물의 결정구조에 대한 실험은 단결정 X-ray 회절 분광법에 의해서 수행되었다. 화합물의 단위포 격자상수는 $a=5.0915(9)\AA$, $b=5.059(1)\AAc=6.156(1)\AA$, $V=120.6(1)\AA3$, $\alpha=65.81(1)^{\circ}$, $\beta=65.56(1)^{\circ}$$\gamma=59.77(1)^{\circ}$이고, 공간 그룹은 P1(Z=2)이다. 화합물의 구조는 704개의 독특한 반사 복사선들에 의해서 결정되었으며, 최종, R값은 0.039이고, wR값은 0.056이다. 이 화합물은 평면삼각형의 BO3그룹과 찌그러진 사면체 구조의 Li04와 ZnO4그룹으로 구성되었으며, Li 원자와 Zn 원자들이 불연속적으로 배열되었다. 번갈아 가면서 불연속적으로 배열된 원자의 충진율은 각각 원자들, Li1, Li2, Zn1 와 Zn2 격자위치에서 약 50%이었다.

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장기복무 직업군인의 긍정성과 가족의사소통이 조직몰입에 미치는 영향과 자기효능감의 매개효과 (The Effects of Positivity and Family Communication on Organizational Commitment and the Mediating Effects of Self-Efficacy between Them among Long-Term Professional Soldiers)

  • 김정은
    • 한국콘텐츠학회논문지
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    • 제16권12호
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    • pp.281-290
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    • 2016
  • 본 연구는 직업군인의 긍정성과 가족의사소통이 조직몰입에 미치는 영향을 확인하고 이들의 관계에서 자기효능감의 매개효과를 알아보는 것이 목적이다. 이를 위해 2015년 국방부의 승인을 거친 직업군인들에 대한 연구에 대해 육 해 공 해병대 부대의 협조를 구하여 장기복무 직업군인 241명에게 설문조사를 거쳤으며 SPSS 21.0과 AMOS 21.0을 사용하여 분석하였다. 연구결과는 첫째, 장기복무 직업군인의 조직몰입은 긍정성, 가족의사소통 그리고 자기효능감과 모두 정적 상관관계를 가지는 것으로 나타났다. 둘째, 조직몰입에 영향을 미치는 변인을 모두 고려하여 분석한 결과, 측정모형과 구조모형의 적합도는 양호한 것으로 나타났으며 직업군인의 조직몰입에 대해 긍정성과 가족의사소통은 긍정적인 영향을 미치며 이들의 관계에서 자기효능감은 매개효과를 가지는 것으로 나타났다. 이와 같은 연구결과를 토대로 장기복무 직업군인의 조직몰입을 위한 효과적인 함의를 제시하고자 한다.

새이중판 지지격자로 지지된 경수로용 연료봉의 진동특성 (Vibration Characteristics of the PWR Fuel Rod Supported by New Doublet Spacer Grids)

  • 최명환;강흥석;윤경호;김형규;송기남
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.905-910
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    • 2003
  • One of the methods that are used to compare and verify the supporting performance of the spacer grids developed is the vibration characteristic test. A modal test in this paper is performed for a dummy rod 3,847mm tall supported by eight New Doublet (ND) spacer grids. For the vibration test in air, nine accelerometers, one displacement sensor and one shaker are used for acquiring signals, and an I-DEAS TDAS software is employed for analyzing the signals. Also, a finite element (FE) analysis is performed by a beam-spring simple model and a contact model simulating the contact phenomenon between the rod and the fm spring. And then, the result of the FE analysis is compared with that of the modal test. The natural frequencies as well as the mode shapes calculated by the proposed contact models have a greater similarity to the test results than those by the previous beam-spring model. In addition, for grasping whether or not the modal parameters are influenced by where shaking spot is, two kinds of tests are performed; one is for the shaker attached at the fourth span (center), the other is for the shaker at the fifth span that is one span nearer to the bottom of the rod. The latter shows higher MAC than the former. Finally, the vibration displacements are measured in the range of 0.112-0.214mm for the excitation force of 0.25-0.75 N.

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An Research Into The Reactive Safety Action Program for Promoting Aviation Safety Culture

  • Kim, Dae Ho
    • 대한인간공학회지
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    • 제35권3호
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    • pp.165-173
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    • 2016
  • Objective: The objective of this research is to inquire about safety information from the standpoint of its usefulness to suggest the significance of the Reactive Safety Action Program, which serves to promote aviation safety culture. Background: Safety information plays an important role in operating safety programs. Each organization learns lessons from safety information collected from aviation accidents and incidents. When an accident occurs, it is only through safety investigation and a close inquiry on the cause that we can come up with an appropriate countermeasure which would contribute to preventing the recurrence of the same or similar accident. However, the usefulness of safety information produced from unsatisfactory safety investigation is insufficient. Method: This research analyzed the characteristics of aviation accidents, the differences between safety investigations and legal accident investigations in systematic and operative perspectives, and safety culture as a measure to activate reporting systems (compulsory/voluntary). Results: This research defined the investigation scope and processes of safety investigations and legal accident investigations. It also suggested factors such as just culture based on trust, non-punitiveness, confidentiality, the participation of the entire staff through the use of inclusive reporting base, ensuring the independence of the operating organization as a way to promote safety through reporting systems. Conclusion: The organization's effort is the important aspect in obtaining exact and accurate safety information from accidents/incidents. The separate running of SIB (Safety Investigation Board) and AIB (Accident Investigation Board), the systematization of safety information reporting system, and prescribing (legislating) the composition of related organizations are some representative programs. Application: This research inquired experiences that contributed in promoting aviation safety culture in a reactive perspective, and will serve a role in spreading safety culture by enabling the use of application experiences of the aviation field in other domains.

Reduction of Electromagnetic Field from Wireless Power Transfer Using a Series-Parallel Resonance Circuit Topology

  • Kim, Jong-Hoon;Kim, Hong-Seok;Kim, In-Myoung;Kim, Young-Il;Ahn, Seung-Young;Kim, Ji-Seong;Kim, Joung-Ho
    • Journal of electromagnetic engineering and science
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    • 제11권3호
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    • pp.166-173
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    • 2011
  • In this paper, we implemented and analyzed a wireless power transfer (WPT) system with a CSPR topology. CSPR refers to constant current source, series resonance circuit topology of a transmitting coil, parallel resonance circuit topology of a receiving coil, and pure resistive loading. The transmitting coil is coupled by a magnetic field to the receiving coil without wire. Although the electromotive force (emf) is small (about 4.5V), the voltage on load resistor is 148V, because a parallel resonance scheme was adopted for the receiving coil. The implemented WPT system is designed to be able to transfer up to 1 kW power and can operate a LED TV. Before the implementation, the EMF reduction mechanism based on the use of ferrite and a metal shield box was confirmed by an EM simulation and we found that the EMF can be suppressed dramatically by using this shield. The operating frequency of the implemented WPT system is 30.7kHz and the air gap between two coils is 150mm. The power transferred to the load resistor is 147W and the real power transfer efficiency is 66.4 %.

한국 간호교육에 대한 개혁 전망 (A Vision for Nursing Education Reform in Korea)

  • 김모임
    • 대한간호학회지
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    • 제24권2호
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    • pp.313-318
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    • 1994
  • To build a suitable National Health Care System for the coming 21s1 century, Nursing must also be renewed. The future Korea will be united and the majority of its population will raidly consist of the aged. Economically standing on the same level with developed countries the growth of scientific technologies will foster communications, firing astounding changes in the medical field. While the overall life style pattern of Koereans not to mention the structure of diseases undergo change, the possibility that the reckless induction of high-tech health care may only cause medical fees to eascafate. It can전so be expected that the health care system will evolve towards the consumers. Nursing in the 21s1 century will be of two scenarios according to WHO, which presents the role of the nurse. The first scenario is that "a gen-eric health care work force" namely a "care giver" will replace all other health professions. If Nursing does not become the compatent profession fitting to this purpose it will eventually dei out. The second scenario is that nurses who are educated in a well grounded and extensive general background and have command of a specialized area will undertake services varying from health pro-motion to treatment and rehabilitation both direct and indirectly, while supervising other personnel. The nurse here would become the "care giver". To become the necessary health care profession in the 21s1 century, nurses should be provided with more educational opportunities, variating in its con-tents, course, and system, enabling them to grow. Clair Faign points out that the minimal educational entry for the nursing profession is a 4 year undergraduate education in this aspect, now in the time to set the future of Nursing into the course of the first scenario. A new educational system stipulating a baccalaureate nursing degree is in urgent need, and aside from govermental actions nurse themseives should formaily officiallze this process, striving for quality assurance. While considering 6 years nursing education programs, multifarious degree courses for existing 3 years educated nurse should be provided Junior nursing schools must devise measures to grow into baccalaucate institutions, also. Among the existing courses, the Self Study Degree Program should be converted into RN, BSN courese provided by universities, and clinical training for the University on the Air must be supplimented, The possibility of establishing nursing courses into commercial high school programs only jeopardizes the development of the nursing profession.

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3-D Stereo PIV에 의한 비정상 델타윙 유동특성에 대한 연구 (A Study on the Unsteady Flow Characteristics of a Delta Wing by 3-D Stereo PIV)

  • 김범석;이현;김정환;이영호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1672-1677
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    • 2004
  • Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modem air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras($1280pixel{\times}1024pixel$) were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.

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선체 용접부의 균열진전 및 피로수명예측에 관한 연구(II) (A Study of Crack Propagation and Fatigue Life Prediction on Welded Joints of Ship Structure (II))

  • 김경수;심천식;권영빈;고희승;기혁근
    • 대한조선학회논문집
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    • 제45권6호
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    • pp.679-687
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    • 2008
  • The fatigue life of ship structure under cyclic loading condition is made up of crack initiation and propagation stages. For a welding member in ship structure, the fatigue crack propagation life is more important than the fatigue crack initiation life. To calculate precisely the fatigue crack propagation life at the critical welding location, the knowledge of the residual stress sensitivity on the fatigue strength is necessary. In this study, thermo elastic-plastic analysis was conducted in order to examine the effect of residual stress on the fatigue crack propagation life. Also the fatigue crack propagation lives considering residual stress were calculated using fatigue crack growth code, AFGROW, on the basis of fracture mechanics. AFGROW is widely used for fatigue crack growth predictions under constant and variable amplitude loading. The reliability of AFGROW on the fatigue of ship structure was confirmed by the comparison of the estimated results with the fatigue propagation test results.

다양한 손실매질내의 손실특성 개선을 위한 새로운 크로스바 구조의 해석 (Analysis of A New Crossbar Embedded Structure for Improved Attenuation Characteristics on the Various Lossy Media)

  • 김윤석
    • 대한전자공학회논문지TC
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    • 제43권12호
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    • pp.83-88
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    • 2006
  • 본 논문에서는 일반적인 손실매질의 다층구조로 이루어진 마이크로 스트립선로의 손실특성의 개선을 위한 새로운 구조를 제안한다. MIS(도체-부도체-반도체) 구조로 된 전송선로를 해석하기 위하여 기본적으로 특성임피던스와 전파상수의 추출에 기초한 일반적인 특성화 절차가 사용되고, Si와 SiO2층 사이에 0전위를 가진 도체를 일정한 간격의 주기적인 배열로 고안된 새로운 모델의 MIS구조에 대한 유한차분법을 이용한 해석방법이 사용된다. 특히 전송선로에 대한 유전체의 영향을 줄이기 위하여 0전위를 가진 주기적인 결합의 도체로 이루어진 구조가 시간영역의 신호를 통해 시험된다. 다양한 손실률을 가진 불완전 유전체에 따른 전압 및 전류의 크기뿐만 아니라 주파수 의존적인 추출된 전송선로 파라미터와 등가회로 파라미터가 주파수 함수로서 나타내진다. 특히 본 논문에서 제안한 새로운 구조의 불완전 유전체에 대한 전송선로 파라미터가 주파수 함수로 구해진다.

한국전쟁기 육군종군작가단의 작품 활동 (Authors Under the Service of the Army in the Korean War)

  • 신영덕
    • 인문언어
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    • 제1권2호
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    • pp.197-217
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    • 2001
  • The literary products of Authors Under the Service of the Army during the Korean War have been neglected on the whole because of the perception that they were little more than war propaganda. The majority of the works (poetry, serial novels, and short stories) Published by these authors in various Army publications such as Junsunmunhak (Literature of the War Front) and Comet, as well as in regular literary periodicals, supports this perception. Most of these works convey simplistic emotions and stereotypes that project untroubled patriotism and strongly antipathetic sentiments against to the Communist North. The appointed leader of this group, Dock-Kyun Choi regarded the pen as another form of weapon to be used against the Communists in the North, and did not shy away from describing in graphic details the atrocities committed by his enemies. But what truly deserves our attention is the fact that many of the same authors who wrote highly propagandistic works also wrote works that can only be described as antiwar. In these works are depicted as faithfully as possible the human sufferings of the war. These works resist and even question the very ideologies that have brought about the conflict, focusing instead on the dark side of the war -the horrifying deaths, the separation of families, and the displacement of people from their homes, How we are to interpret this ambivalence in many of these authors is a task that remains to be carried out. We must approach these works with more seriousness and begin by comparing them with similar products from authors under the service of the Navy and the Air Force during the Korean War.

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