• Title/Summary/Keyword: Initial Condition

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The Initial Film Flow Development of the High-Pressure Swirl Spray (고압스월분무 액막유동의 초기 발달과정에 대한 연구)

  • Moon, Seok-Su;Abo-Serie, Essam;Choi, Jae-Joon;Bae, Choong-Sik
    • Journal of ILASS-Korea
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    • v.11 no.4
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    • pp.212-219
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    • 2006
  • The initial film flow development of the high-pressure swirl spray was investigated at different injector operating conditions to analyze film flow development and to provide the input data for the modeling works. This result can be also useful to verify the previously simulated results. The initial flow conditions such as liquid film thickness, flow angle and flow divergence are obtained by visualizing the inside and near the nozzle flow with a microscopic imaging system. The visualized images are quantified using an image processing tool. From the information of liquid film thickness and flow angle, the initial axial and tangential velocity and the swirl number of the swirl spray are successfully determined at various operating conditions. The experimental results showed that the initial liquid film thickness, flow angle and flow divergence are remained constant when the injection pressure is increased. However, initial film conditions are severely changed when the fuel temperature is increased. The swirl number remained constant when the injection pressure is increased while it showed increased value at high fuel temperature condition.

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Characteristic Analysis of the Coefficient of Initial Abstraction and Development of its Formular in the Rural Watersheds - for the Small-Medium Watersheds in the Geum and Sapkyo River - (농촌유역에서의 초기강우손실 특성분석과 계수 산정식 개발 - 금강.삽교천 중소유역을 중심으로-)

  • Kim, Tai-Cheol;Lee, Jeong-Seon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.6
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    • pp.3-12
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    • 2008
  • It is important to estimate accurate effective rainfall to analyse flood flow and long-term runoff for the rational planning, design, and management of water resource. The initial abstraction is also important to estimate effective rainfall. The Soil Conservation Service (SCS) has developed a procedure and it has been most commonly applied to estimate effective rainfall. But the SCS method still has weak points, because of unnatural assumptions such as antecedent moisture conditions and initial abstraction. The coefficient of initial abstraction(K) is depending on the soil moisture condition and antecedent rainfall. The maximum storage capacity of Umax which is calibrated by stream flow data in the proposed watershed was derived from the DAWAST(DAily WAtershed STreamflow) model. The values of K obtained from 69 storm events at the five watersheds are ranging from 0.133 to 0.365 and its mean value is 0.207. Effective rainfall could be estimated more reasonably by introducing new concept of initial abstraction. The equation of $K=0.076Sa^{0.255}$ was recommended instead of 0.2 and it could be applicable to the small-medium rural watersheds.

Postpneumonectomy Empyema That Occurred 27 1/2 Years After Initial Pneumonectomy -A Case Report- (전폐절제술후 27년 6개월에 발생한 농흉 치험 -1례 보고-)

  • 이광선
    • Journal of Chest Surgery
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    • v.28 no.5
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    • pp.504-506
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    • 1995
  • Postpneumonectomy empyema is an infrequent but dreaded complication. The seriousness of this complication is impossible to eliminate the space containing the infection, and consequently, it is difficult to sterilize the space. The time from pneumonectomy to the development of an empyema ranges from several days to several years, with most evident with 4 weeks. We experienced a case of postpneumonectomy empyema that occurred 27 1/2 years after initial pneumonectomy. She was treated with intrapleural antiseptic irrigation and open-tube drainage following partial decortication. The patient had an uneventful recovery and was discharged from hospital with improved condition.

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GLOBAL EXISTENCE AND NONEXISTENCE OF SOLUTIONS FOR COUPLED NONLINEAR WAVE EQUATIONS WITH DAMPING AND SOURCE TERMS

  • Ye, Yaojun
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.6
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    • pp.1697-1710
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    • 2014
  • The initial-boundary value problem for a class of nonlinear higher-order wave equations system with a damping and source terms in bounded domain is studied. We prove the existence of global solutions. Meanwhile, under the condition of the positive initial energy, it is showed that the solutions blow up in the finite time and the lifespan estimate of solutions is also given.

Excimer-Laser Annealing for Low-Temperature Poly-Si TFTs

  • Kim, Hyun-Jae
    • Journal of Information Display
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    • v.4 no.4
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    • pp.1-3
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    • 2003
  • For excimer laser annealing (ELA), energy density, number of pulses, beam uniformity, and condition of initial amorphous Si (a-Si) films are significant factors contributing to the final microstructure and the performance of low-temperature polycrystalline Si (LTPS) TFTs. Although the process and equipment have been significantly improved, the environmental factors associated with initial amorphous Si (a-Si) films and process conditions are yet to be optimized.

An overlapping decomposed filter for INS initial alignment (관성항법장치의 초기정렬을 위한 중복 분해 필터)

  • 박찬국;이장규
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.136-141
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    • 1991
  • An Overlapping Decomposed Filter(ODF) accomplishing an initial alignment of an INS is proposed in this paper. The proposed filter improves the observable condition and reduces the filtering computation time. Its good performance has been verified by simulation. Completely observable and controllable conditions of INS error model derived from psi-angle approach are introduced under varying sensor characteristics vary. The east components of gyro and accelerometer have to be the first order markov process and the rest of them are the characteristics of the random walk or first order markov process.

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A Study on the Hemisphere-Type Compression Molding for Continous Fiber-Reinforced Polymeric Composites (연속섬유강화 플라스틱 복합재료의 반구형 압축성형성에 관한 연구)

  • 임용진;오영준;김이곤
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.149-153
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    • 1999
  • During a hemisphere-type compression molding, the wrinkles are caused by complex stress condition. It is very important to clarify the degree of wrinkles in order to have good products. In this paper, the effects of numbers of needling and initial area on the degree of wrinkles are studied. the degree of wrinkle is expressed as nonhomogeneity.

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DIFFERENTIAL EQUATIONS ON CLOSED SUBSETS OF A PROBABILISTIC NORMED SPACE

  • Kim, Jong-Kyu;Jin, Byoung-Jae
    • Journal of applied mathematics & informatics
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    • v.5 no.1
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    • pp.223-233
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    • 1998
  • This paper is concerned with the problem of existence of solutions to the initial value problem u'(t) = A(t, u(t)), u(a) = z in a probabilistic normed space where $A : [a,b)\;{\times}\;D->E$ is continuous, D is a closed subset of a probabilistic normed space E, and $z\;{\in}\;D$. With a dissipative type condition on A, we estabilish sufficient conditions for this initial value problem to have a solution.

Excimer-Laser Crystallization for Low-Temperature Polycrystalline Si TFTs

  • Kim, Hyun-Jae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.151-152
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    • 2000
  • For excimer laser crystallization (ELC), energy density, number of pulses, beam uniformity, and condition of initial amorphous Si (a-Si) films are significant factors contributing the final microstructure and the performance of low-temperature polycrystalline Si TFTs. The process and equipment have been achieved a significant improvement, but still, environmental factors associated with initial amorphous Si (a-Si) films and process conditions need to be optimized.

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