• 제목/요약/키워드: Pattern region

검색결과 1,922건 처리시간 0.027초

원심 다익홴의 유동에 대한 컷 오프 각도의 영향 (Effect of Cut-off Angle on Flow Pattern of Centrifugal Multi-blade Fan)

  • 강경준;신유환;이윤표;김광호
    • 한국유체기계학회 논문집
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    • 제13권3호
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    • pp.37-42
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    • 2010
  • This study investigated on details of flow characteristics of a multi-blade fan for domestic ventilation. Experiments and analysis were carried out to describe on flow pattern with variations of cut-off angle near the scroll housing throat, which were performed by PIV measurement for the flow field and by total pressure probes. The stagnation point at cut-off region of the fan moves to the exit of the scroll housing as the cut-off angle increases. The movement of stagnation point and the variation of throat area of the scroll housing influence to the distribution of velocity magnitude at the exit of the fan. Furthermore, a large distortion of the velocity distribution at the scroll exit causes to increase mixing loss along the flow path.

한글 자음의 주파수 분석적인 연구 (Study on the Korea Consonont by Frequency Analyzing)

  • 신용철;최진태
    • 대한전자공학회논문지
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    • 제10권3호
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    • pp.61-68
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    • 1973
  • 한글 자음을 sona-grap로 부터 얻은 음성 pattern으로 주파수분석적인 방법으로 정밀분석한다는 것은 지극히 곤란한 것이며 주파수합성적인 방법으로 연구해야 할 문제임을 알았다. 그래서 자음 주파수영역을 분석추출하였으며, 전자음에 후독하는 $\mid$$\mid$의 format가 조음방법과 조음위치와 대응해서 변화하는 상태를 주로 관찰하였다.

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Electroforming을 이용한 PDP용 EMI 메시 개발 (EMI Mesh Development for the PDP using Electroforming)

  • 권혁홍;범민욱;임성룡;황춘섭;박동식;이태환
    • 한국생산제조학회지
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    • 제20권1호
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    • pp.108-113
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    • 2011
  • There are a lot of PDP TV for a plasma discharge pulse voltage generated by the use of electromagnetic waves. EMI mesh film is near Infrared ray caused by malfunction of the remote control intended to prevent this phenomenon. In this study, the formation of fine pattern by making the mold is imprinted on the film sheet. EMI mesh film has been granted by filling in the conductive material region imprinted with electroforming in the manufacture of resistance. The fine patterns fabricated with electroforming facility thickness of homogenization process technology were established to optimize the working conditions.

Effects of PCB Ground Plane and Case on Internal WLAN Patch Antenna

  • Kim, H.T.;Heo, J.K.;Jeong, K.J.;Hwang, S.W.
    • 전기전자학회논문지
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    • 제11권4호
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    • pp.252-256
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    • 2007
  • We demonstrate that the effect of the PCB ground length and the cover is important in the performance of 2.4 GHz patch antennas. The Center frequency in the return loss shifts as much as 0.5 GHz, when the length of the PCB ground increases from 30 to 85 mm. The position of 10-dB bandwidth accordingly shifts to lower frequency region. Finally, the resonance at 2.4 GHz becomes stronger when the top cover exists. The radiation pattern of the patch antenna is also strongly affected by the ground structure and the existence of the top cover. In both the return loss and the radiation pattern, 3-dimensional simulations are shown to be an efficient tool.

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소구경 배관내 아이스슬러리의 유동형상 및 압력강하 특성에 관한 실험적 연구(1) (Experimental Study on Flow Patterns and Pressure Drop Characteristics of Ice Slurry In Small Size Pipe (1))

  • 이동원;윤찬일;윤응상
    • 설비공학논문집
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    • 제14권5호
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    • pp.385-390
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    • 2002
  • To clarify the hydraulic characteristics of ice slurry which made from 6.5% ethylene glycol-water solution flowing through circular pipes of small diameter, experimental studies were performed. The flow pattern was observed and the pressure drop was measured in acrylic pipes with inner diameter of 24 mm. The results of flow visualization revealed that ice particles flowed along the top of pipes in the ranges of small ice fraction and low flow rate, while Ice particles diffused into the whole region of pipes flowed like a homogeneous flow for high flow rate and high ice fraction. An increase in frictional pressure drop was measured as the ice fraction increased in all pipes and unstable flow was observed for up-ward vertical pipe.

Long lived spiral structures in galaxies

  • Saha, Kanak
    • 천문학회보
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    • 제42권1호
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    • pp.31.1-31.1
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    • 2017
  • Spiral structure in disk galaxies is modeled with ncollisionless N-body simulations including live disks, halos, and bulges with a range of masses. Two of these simulations make long-lasting and strong two-arm spiral wave modes that last for about 5 Gyr with constant pattern speed. These two had a light stellar disk and the largest values of the Toomre Q parameter in the inner region at the time the spirals formed, suggesting the presence of a Q-barrier to wave propagation resulting from the bulge. The relative bulge mass in these cases is about 10%. Models with weak two-arm spirals had pattern speeds that followed the radial dependence of the Inner Lindblad Resonance. In addition to these, we also report a few more cases where two-armed spirals are developed and are maintained for a several rotation time scales.

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Integrated Approach of Multiple Face Detection for Video Surveillance

  • Kim, Tae-Kyun;Lee, Sung-Uk;Lee, Jong-Ha;Kee, Seok-Cheol;Kim, Sang-Ryong
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 Ⅳ
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    • pp.1960-1963
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    • 2003
  • For applications such as video surveillance and human computer interface, we propose an efficiently integrated method to detect and track faces. Various visual cues are combined to the algorithm: motion, skin color, global appearance and facial pattern detection. The ICA (Independent Component Analysis)-SVM (Support Vector Machine based pattern detection is performed on the candidate region extracted by motion, color and global appearance information. Simultaneous execution of detection and short-term tracking also increases the rate and accuracy of detection. Experimental results show that our detection rate is 91% with very few false alarms running at about 4 frames per second for 640 by 480 pixel images on a Pentium IV 1㎓.

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수원(水原) 근교(近郊)에서 분리(分離)한 Chlorella ellipsoidea의 필수(必須) Amino 산(酸) 조성(組成)에 관(關)한 연구(硏究) A study on the Essential Amino Acid Composition of Chlorella ellipsoidea Isolated Near Suwon (A Study on the Essential Amino Acid Composition of Chlorella ellipsoidea Isolated Near Suwon)

  • 정영건
    • Journal of Nutrition and Health
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    • 제9권2호
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    • pp.98-101
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    • 1976
  • The essential amino acids composition of Green algae (chlorella ellipsoidea) that was isolated near the suwon was compared with that of soy flour and the provisional pattern of amino acids of reference protein of FAO and found that the limit amino acid was methionine. The rest of essential amino acids were distributed widely and abunduntly. While soy flour was defficient in methionine and valine on comparing with the provisional pattern. Slightly more content of methionine was recognized in chlorella protein than that of spirulina maxima which was reported to be eaten in the Lake Chard region of Africa and Mexico as a daily food. It was concluded that good quality protein is able to be synthesised from the wild alage if a qualified alage media was given to them.

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방위각방향 온도변화를 가지는 실린더 내의 부력 유동 (Buoyant Convection in a Cylinder with Azimuthally-varying Sidewall Temperature)

  • 정광효;현재민;송태호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집B
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    • pp.45-50
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    • 2000
  • A numerical investigation is made of three-dimensional buoyant convection of a Boussinesq-fluid in a vertical cylinder. The top and bottom endwalls are thermally insulated. Flow is driven by the substantial azimuthal variations in thermal boundary conditions. Comprehensive numerical solutions to the Navier-Stokes equations are obtained. The representative Rayleigh number is large, thus, the overall flow pattern is of boundary layer-type. Three-dimensional (low characteristics are described. Specially, the global flow and the heat transfer features are delineated when the severity of azimuthal variation of sidewall temperature n, is intensified. Temperature and velocity fields on the meridional planes and the planes of constant height are presented. The global flow weakens as n becomes large. The pattern of the local Nusselt number on the surface of cylinder is similar regardless of n. The convective gain in heat transfer activities is reduced as n increases.

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CLUSTER ANALYSIS FOR REGION ELECTRIC LOAD FORECASTING SYSTEM

  • Park, Hong-Kyu;Kim, Young-Il;Park, Jin-Hyoung;Ryu, Keun-Ho
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.591-593
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    • 2007
  • This paper is to cluster the AMR (Automatic Meter Reading) data. The load survey system has been applied to record the power consumption of sampling the contract assortment in KEPRI AMR. The effect of the contract assortment change to the customer power consumption is determined by executing the clustering on the load survey results. We can supply the power to customer according to usage to the analysis cluster. The Korea a class of the electricity supply type is less than other country. Because of the Korea electricity markets exists one electricity provider. Need to further divide of electricity supply type for more efficient supply. We are found pattern that is different from supplied type to customer. Out experiment use the Clementine which data mining tools.

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