• Title/Summary/Keyword: Internal/External flow

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Technological Innovation Capacity Evaluation And Technology Diffusion Analysis Using Patent Data (특허정보를 이용한 기술혁신능력 평가 및 기술 확산 분석)

  • Nam, Ki-Woong;Park, Sang-Sung;Shin, Young-Geun;Jang, Dong-Sik
    • Proceedings of the KAIS Fall Conference
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    • 2009.05a
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    • pp.319-324
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    • 2009
  • Lately, knowledge-based society comes, it is important for enterprises to creatively utilize knowledge of technology for technological innovation. So, Technological innovation capacity of enterprises is important factor of business success. To improve technological innovation capacity, enterprises should well utilize their internal knowledges and external knowledges which come from technological diffusion. To well utilize external knowledges of enterprises they should well understand external knowledge flow. Especially knowledge flow also occurs frequently between nations, understanding of knowledge flow which occurs between nations is important to improve nation`s technological innovation capacity. So this paper presents comparison of technological innovation capacity and knowledge diffusion flow between nations.

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External Treatment of Carcinous pain in Journal of Chinese Medicine (중의치험례(中醫治驗例)를 중심(中心)으로 살펴본 암성(癌性) 동통(疼痛)의 외치법(外治法))

  • Lee, Yoon-Hee;Shin, Min-Kyu;Byun, Joon-Seok
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.6 no.1
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    • pp.113-123
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    • 2000
  • Carcinous pain is severe and continuous so difficult to alleviate. Western drugs give rise to reaction such as anorexia, constipation, vomiting, general weakness and dyspnea, And they cause tolerence. External treatment is a way to put a patch or rub a liquid on the skin. The patch and liquid are made from herb medicine. In china, they have a good effect of alleviating carcinous pain to make use of external treatment. Usually they use the medicine with effect of reprecussion (消腫), removing obstruction(散結), activating blood flow and removing blood stasis (活血化瘀) such like Borneloum(?片). Bufonis Venenum (蟾?), Aconiti ciliane Tubber(草烏), Arisaematis Rhizoma(南星), Asari herba cum Radice (細辛) etc. We can get the alleviating effect more quickly and prevent reaction through external treatment.

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Preparation of the Internal Mammary Artery Graft in Coronary Artery Bypass Surgery - Comparison of Free Mammary Artery Flows - (관상동맥 우회로술에서 내유동맥 이식편의 처치방법에 따른 문합전 내유동맥 혈류량의 비교)

  • 최종범;김형곤;정진원
    • Journal of Chest Surgery
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    • v.26 no.2
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    • pp.148-153
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    • 1993
  • To compare two methods of mammary pedicle graft preparations with free internal mammary artery flow, we studied 31 patients who had the left internal mammary artery harvested for coronary artery bypass grafting. The free flow was measured at the transected opening of 2 to 3 cm distal to the point of bifurcation on mean arterial pressure of 50 to 55 mmHg during cardiopulmonary bypass. Group I comprised 14 patients, whose grafts were sprayed and wrapped in sponges soaked in diluted papaverine solution (60 mg in 40 ml Hartmann's solution). An average 80 minutes after the preparations, free flow of the internal mammary artery ranged from 20 to 80 ml/min (mean 37.7 ml/min). Group II comprised 17 patients, who had internal mammary artery takedown under the exact conditions used in group I. The grafts were sprayed and wrapped in sponges soaked in the diluted papaverine solution as in group I. After an average of 28 minutes, free flow ranged from 8 to 28 ml/min (mean 17.6 ml/min). Intraluminal papaverine of the same dilution was then injected without any hydrostatic dilatation and flows increased upto 37 to 150 ml/min (mean 74.7 ml/min). This study shows that intraluminal papaverine preparation method markedly increases free mammary artery flow which is inadequate with external papaverine preparation.

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Numerical Simulation of Boiling 2-Phase Flow in a Helically-Coiled Tube (나선형코일 튜브 비등2상 유동 수치해석)

  • Jo J. C.;Kim W. S.;Kim H. J.;Lee Y. K.
    • 한국전산유체공학회:학술대회논문집
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    • 2004.03a
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    • pp.49-55
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    • 2004
  • This paper addresses a numerical simulation of the flow and heat transfer in a simplified model of helically coiled tube steam generator using a general purpose computational fluid dynamic analysis computer code. The steam generator model is comprised of a cylindrical shell and helically coiled tubes. A cold feed water entered the tubes is heated up, evaporates. and finally become a superheated steam with a large amount of heat transferred continuously from the hot compressed water at higher pressure flowing counter-currently through the shell side. For the calculation of tube side two-phase flow field formed by boiling, inhomogeneous two-fluid model is used. Both the internal and external turbulent flows are simulated using the standard k-e model. The conjugate heat transfer analysis method is employed to calculate the conduction in the tube wall with finite thickness and the convections in the internal and external fluids simultaneously so as to match the fluid-wall-fluid interface conditions properly. The numerical calculations are peformed for helically coiled tubes of steam generator at an integral type pressurized water reactor under normal operation. The effects of tube-side inlet flow velocity are discussed in details. The results of present numerical simulation are considered to be physically plausible based on the data and knowledge from previous experimental and numerical studies where available.

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Characteristics of Internal Flow and Fuel Spray in a Fuel Nozzle Orifice (연료노즐의 내부유동 및 외부분무 특성)

  • Hong, S.T.;Park, J.H.;Koo, J.Y.
    • Journal of ILASS-Korea
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    • v.1 no.1
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    • pp.76-84
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    • 1996
  • The nozzle geometry and up-stream inject ion condition affect the characteristics of flow inside the nozzle. such as turbulence and cavitation bubbles. Flow details in fuel nozzle orifice with sudden contraction of cross sectional area have been investigated both experimentally and numerically. The measurements of velocities of internal flow in a scaled-up nozzle with different length to diameter rat io(L/d) were made by laser Doppler velocimetry in order to clarify the effect of internal flow on the characteristics of fuel spray. Mean and fluctuating velocities and discharge coefficients were obtained at various Reynolds numbers. The turbulent intensity and turbulence kinetic energy in a sharp inlet nozzle were higher than that in a round inlet nozzle. Calculations were also performed for the same nozzles as scaled-up experimental nozzles using the SIMPLE algorithm. External spray behavior under different nozzle geometry and up-stream flow conditions using Doppler technique and visualization technique were also observed.

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Hydraulic Model Experiment on the Circulation in Sagami Bay, Japan (II) - Dependence of the Circulation Pattern on External and Internal Rossby Number in Baroclinic Rotating Model

  • Choo Hyo-Sang;Sugimoto Takasige
    • Fisheries and Aquatic Sciences
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    • v.5 no.1
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    • pp.5-20
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    • 2002
  • To investigate the effect of mechanical parameters on the circulation and its fluctuation in Sagami Bay, baroclinic model experiments were carried out by use of a two-layer source-sink flow in a rotating tank. In the experiment, a simple coastal topography with flat bottom was reproduced. The results show that the path of the Through Flow, which corresponds to the branch current of the Kuroshio, depends on external Rossby number (Ro) and internal Rossby number $(Ro^*)$, and divided into two regimes. For $Ro^*\leq1.0$ in which Rossby internal radius of deformation of the Through Flow is smaller than the width of the approaching channel, the current flows along the Oshima Island as a coastal boundary density current separated from the western boundary of the channel. For $Ro^*>1.0$ it changes to a jet flow along the western boundary of the channel, separated from the coast of Oshima Island. The current is independent on both Ro and Ro* in the regime of $Ro^*>1.0,\;Ro\geq0.06$ and $Ro^*\leq1.0,\;Ro\geq0.06$. The pattern of the cyclonic circulation in the inner part of the bay is also determined by Ro and Ro*. In case of $Ro^*\leq1.0$, frontal eddies are formed in the northern boundary of the Through Flow. These frontal eddies intrude into the inner part along the eastern boundary of the bay providing vorticity to form and maintain the inner cyclonic circulation. For $Ro^*>1.0$, the wakes from the Izu peninsula are superposed intensifying the cyclonic circulation. The pattern of the cyclonic circulation is divided into three types; 1) weak cyclonic circulation and the inner anticyclonic circulation $(Ro<0.12)$. 2) cyclonic circulation in the bay $(0.12\leq Ro<0.25)$. 3) cyclonic circulation with strong boundary current $(RO\geq0.25)$.

A study on understanding the deduction system in the proof (증명에서 연역 체계 이해에 관한 연구)

  • Kang, Jeong Gi;Roh, Eun Hwan
    • The Mathematical Education
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    • v.52 no.4
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    • pp.549-565
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    • 2013
  • To help students understand the deduction system in the proof, we analyzed the textbook on mathematics at first. As results, we could find that the textbook' system of deduction is similar with the Euclid' system of deduction. The starting point of deduction is different with each other. But the flow of deduction match with each other. Next, we searched for the example of circular argument and analyzed. As results, we classified the circular argument into two groups. The first is an internal circular argument which is a circular argument occurred in a theorem. The second is an external circular argument which is a circular argument occurred between many theorems. We could know that the flow of deduction system is consistent in internal-external dimension. Lastly, we proposed the desirable teaching direction to help students understand the deduction system in the proof.

Analysis of leakage factors affecting ECV performance in variable compressor

  • Mahmud, Md. Iqbal;Cho, Haeng Muk
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.183-188
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    • 2014
  • Solenoid operated electromagnetic control valve (ECV) using in an external variable displacement swash plate type compressor is widely used for air conditioning control system because of its low energy consumption and high efficient characteristics. ECV controls the entire vehicle air conditioning system by means of a pulse width modulation (PWM) system that supplied from an external controller. Different pressure ports located within ECV has important functions to control the air/refrigerant flow through its internal passages. The flow paths are preciously maintained with acceptable ranges of leakage (gap) between the parts inside it which is followed by effective design and critical dimensioning of its internal features. Therefore, it saves energy losses from the solenoid operation as well as ensures the balance of forces within it. The research paper highlights analysis of the leakages (at different pressure ports) and dimensioning tolerance factors that affects the ECV performance.

Dynamics of Coaxial Swirl Injectors in Combustion Environment (연소 조건하의 동축형 분사기의 동적 특성 고찰)

  • Seo Seonghyeon;Han Yeoung-Min;Lee Kwang-Jin;Kim Seung-Han;Seol Woo-Seok;Lee Soo-Yong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.10a
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    • pp.282-287
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    • 2004
  • Unielement combustion tests were conducted using coaxial bi-swirl injectors. Major experimental parameters were a recess length and a fuel-side swirl chamber. Combustion efficiency mainly depends on a mixing mechanism for the present coaxial swirl injectors. Low-frequency pressure excitations around 200Hz were observed for all injectors. However, dynamic behaviors considerably differ for an external and an internal mixing case controlled by a recess length. The internal mixing induces mixture to be biased at a specific frequency in a mass flow rate, which results in a relatively high amplitude of pressure fluctuations but results for the external mixing case show that fuel and oxidizer mixture flow carries more complicated, multiple wave characteristics due to broad mixing region as well as disintegration and merging phenomena of propellant films.

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