• Title/Summary/Keyword: divergent

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A Design Process of Digital System in Polymachine Image (복합 기계 상에 의한 디지탈 시스템의 일반계 과정)

  • 김현재
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.19 no.6
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    • pp.9-16
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    • 1982
  • This is an introduction to an art of digital hardware design using polymachine image as a target structure of the product. As in the case of software design of a computer, the design process begins with a sketch of planned system in flow chart description and the flow charts is partitioned into divergent elements. Each of the element machine is derived from those divergent elements. We can build a complete digital system with the preparation of an index, and a polymer of these element machines.

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The Effects of Wall Elasticity on Wall Shear Rate of a Divergent Tube (Vascular Graft) (벽 탄성도가 확장관(인조혈관) 벽 전단변형률에 미치는 영향)

  • Rhee, Kye-Han;Lee, Sang-Man
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.23 no.6 s.165
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    • pp.912-921
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    • 1999
  • Shear stress acting on the arterial wall by blood flow is an important hemodynamic factor influencing blocking of blood vessel by thickening of an arterial wall. In order to study the effects of wall elasticity on the wall shear rate distribution in an artery-divergent graft anastomosis, a rigid and a elastic model are manufactured. These models are placed in a pulsatile flow loop, which can generate the desired flow waveform. Flow visualization method using a photochromic dye is used to measure the wall shear rate distribution. The accuracy of measuring technique is verified by comparing the measured wall shear rate in the straight portion of a model with the theoretical solution. Measured wall shear rates depend on the wall elasticity and flow waveform. The mean and maximum shear rate in the elastic model are lower than those in rigid model, and the decreases are more significant near the end of a divergent tube. The reduction of mean and maximum of wall shear rate in an elastic model are up to 17 percent.

A Study on the Impulse Waves Discharged from the Exit of the Convergent/Divergent Pipes (축소/확대관 출구로부터 방출되는 펄스파에 관한 연구)

  • Lee, D.H.;Ju, K.M.;Kim, H.S.;Kim, H.D.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.640-645
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    • 2001
  • The present study is to investigate the characteristics of the impulse waves discharged from the exit of the convergent and divergent pipes. An experiment is carried out using a shock tube with an open end and is compared to the computation of the axisymmetric, compressible, unsteady Euler equations, which are solved by the second-order total variation diminishing(TVD) scheme. For the computational work, some initial compression waves are assumed inside the pipe so that those are identical to the experimental ones of the shock tube. The results show that the peak pressures of the impulse waves discharged from the exit of convergent and divergent pipes decrease with an increase in the wavelength of the initial compression wave. All of the impulse waves have a strong directivity toward the pipe axis, regardless of the exit type of the pipe employed. The impulse waves discharged from the divergent pipe are stronger than those from the straight pipe, while the impulse waves of the convergent pipe are weaker than those from the straight pipe. It is believed that the convergent pipe can playa role of a passive control to reduce the peak pressure of the impulse wave. The present computations represent the experimented impulse waves with a good accuracy.

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Effect of Rib Pitch on Heat Transfer and Friction Factor in a Two Wall Divergent Channel (2벽면 확대 사각채널에서 리브 피치가 열전달과 마찰계수에 미치는 효과)

  • Ahn, Soo Whan;Lee, Myung Sung;Jeong, Seong Soo;Bae, Sung Taek
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.26 no.4
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    • pp.175-180
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    • 2014
  • Experimental investigations of the heat transfer and friction factors in the ribbed divergent rectangular channel with the channel exit hydraulic diameter to inlet hydraulic diameter ratio of 1.16 were performed. The surface heaters were mounted onto the two opposite walls. The main experimental parameter is the ratio of rib pitch (p) to height (e), at which the ratios (p/e) of 6, 10, and 14 are considered in the channel with ribs on one wall only. The straight ribbed square channel is also considered as a comparison. The major findings are that the ratio of p/e = 6 shows the highest values in the heat transfer and the ratio of p/e = 10 indicates the greatest friction factor in the ribbed divergent channel. Editor's note:No major changes or corrections needed. Well written.

Target extraction using divergent-direction-emphasis symmetry transform (발산 방향성 강조 대칭변환을 이용한 표적 검출)

  • Jun, Jun-Hyung;Lee, Hee-Yul;Choi, Byung-Jae;Park, Kil-Houm
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.5
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    • pp.665-671
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    • 2010
  • This paper propose the DDEGST(divergent-direction-emphasis generalized symmetry transform) which emphasis the symmetry of divergent intensity orientation for effective target extraction in FLIR(forward looking infra-red) images. In the proposed method, we use the exponential function instead of cosine function as a phase weight function in the generalized symmetry transform for effective target extraction in FLIR images which contain a target with higher intensity than a background intensity. To evaluate the performance of the proposed method, we compare the proposed mehtod with conventional GST method in experiments. We prove that the proposed method have better performance in IR images.

Heat Transfer Enhancement in a Divergent Passage with 30° Inclined Ribs (30° 경사 리브가 있는 확대 채널 통로 내의 열전달 증가)

  • Lee, Myung Sung;Ahn, Soo Whan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.29 no.8
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    • pp.401-407
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    • 2017
  • The effect of different rib geometries such as V-shaped continuous (case A), parallel broken (case B), and V-shaped broken (case C) ribs on local heat transfer distributions and pressure drops in a divergent channel with $30^{\circ}$ inclined ribs on one wall or two walls was investigated for Reynolds numbers from 22,000 to 75,000. Top and bottom walls were insulated; two side walls were uniformly heated in the divergent channel. Heated walls were composed of 10 isolated coper sections and length-to-outlet hydraulic diameter ratio of 10. Rib height-to-outlet hydraulic diameter ratio was 0.1, and rib pitch-to-height ratio equaled 10. Results revealed that V-shaped continuous rib (case A) produced approximately 1.4 times higher average Nussselt number than in the parallel broken rib (case B), and V-shaped broken rib (case C) in the channel with two ribbed walls at Re = 54,000.

Cultural Differences of Professional Organizations in Wholesale Seafood Markets (수산물 도매시장의 유통조직별 문화의 차이)

  • Kim, Jin-Baek
    • The Journal of Fisheries Business Administration
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    • v.40 no.3
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    • pp.107-125
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    • 2009
  • Research on culture has been widespread across social science researches. But there has not been any cultural research in the fisheries industry. This study tried to identify whether the culture of the fishery organization had a convergent or divergent characteristic. To do so, fishery distributors and wholesalers, who affiliated with their professional associations or wholesale seafood markets, were surveyed across supplying and consuming areas(Busan and Seoul). If fishery organizations have always been culture-bound, rather than culture free, then their members show the divergent characteristic of culture. Despite a similarity in tasks, size and market segments, if this fact is proved, fishery distributors and wholesalers in different areas will differ in many of their managerial practices such as marketing policies, communication patterns, motivation techniques, etc. And it is expected that national and industrial cultures are major determinants of their behaviors. Depending on the results of this study, fishery distributors and wholesalers had a divergent characteristic. So, it was concluded that fishery distributors and wholesalers of wholesale seafood markets in supplying area were different from those in consuming area. It was found that this difference was attributed to individualism/collectivism and masculinity/femininity dimensions. In individualism/collectivism dimension, fishery distributors and wholesalers of consuming area were stronger than those of supplying area. That is, fishery distributors and wholesalers of consuming area were more collective than those of supplying area. But in masculinity/femininity dimension, fishery distributors and wholesalers of supplying area were stronger than those of consuming area. And the divergent characteristic was moderated by demographic variables (gender, age, education level, career). Especially, masculinity/femininity dimension was more moderated by demographic variables than individualism/ collectivism dimension.

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The Effect of CPS Programming Model on promoting Elementary school students' divergent thinking (초등학생의 확산적 사고 촉진을 위한 CPS 프로그래밍 수업의 효과 분석)

  • Jeon, Seong-Kyun;Lee, Young-Jun
    • The Journal of Korean Association of Computer Education
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    • v.15 no.2
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    • pp.1-8
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    • 2012
  • General form of the programing education is finding and realizing algorithm to solve problems faster and more efficiently. In other words, it is based on convergent thinking. However, the programming education must have different characteristics to education targets. For elementary school students, it is needed to provide various experience-centered investigation environments. They should learn how to find the most efficient problem solving method by themselves. This study had adopted divergent thinking strategy where divergent thinking and convergent thinking can be repeated at the same time to suit a programming education with great importance of convergent thinking to elementary school leaners, and analyzed its effects. This study was applied to 5th graders, and 12 times of experimental measure classes were conducted by dividing them into the control group that conducted general programming class and the experimental group that conducted a programming class including divergent thinking of CPS model. As a result, CPS model had significant effect on the subordinate elements of creative problem solving skills, self-assurance, independence, and divergent thinking.

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Aerodynamic Performance Improvement by Divergent Trailing Edge Modification to a Supercritical Airfoil

  • Yoo, Neung-Soo
    • Journal of Mechanical Science and Technology
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    • v.15 no.10
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    • pp.1434-1441
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    • 2001
  • A computational study has been performed to determine the effects of divergent trailing edge (DTE) modification to a supercritical airfoil in transonic flow field. For this, the computational result with the original DLBA 186 supercritical airfoil was compared to that of the modified DLBA 283. A wavier-Stokes code, Fluent 5. 1, was used with Spalart-Allmaras's one-equation turbulence model. Results in this study showed that the reduction in drag due to the DTE modification is associated with weakened shock and delayed shock appearance. The decrease in drag due to the DTE modification is greater than the increase in base drag. The effect of the recirculating flow region on lift increase was also observed. An airfoil with DTE modification achieved the same lift coefficient at a lower angle of attack while giving a lower drag coefficient. Thus, the lift-to-drag ratio increases in transonic flow conditions compared to the original airfoil. The lift coefficient increases considerably whereas the lift slope increases just a little due to DTE modification.

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The Relationship between Fixation and Brain Preference (고착(Fixation)과 뇌활용성향과의 관계)

  • Lee, Hong;Jun, Yun-sook;Park, Eun-a
    • Knowledge Management Research
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    • v.6 no.1
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    • pp.85-103
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    • 2005
  • The purpose of this study was to identify the relationship between fixation and brain preference. Based on the hemisphere asymmetric theory and fixation, two hypotheses were articulated. They were: 1) Right-brain preference is negatively related to divergent fixation. 2) Left-brain preference is negatively related to convergent fixation. A self-reporting scale for measuring the brain preference with 42 items were developed for the study based on functional characteritics of left and right hemisphere. Samples were collected from 579 college students in K University. Regression analysis showed that right-brain preference was negatively associated with divergent fixation. In the relationship between left-brain preference and convergent fixation, mixed results were produced. Research implication were discussed at the end of the study.

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