• 제목/요약/키워드: rotation rate

검색결과 817건 처리시간 0.03초

살색과 얼굴 특징들의 기하학적 제한을 이용한 얼굴 위치 찾기 (Face Detection Using Skin Color and Geometrical Constraints of Facial Features)

  • 조경민;홍기상
    • 전자공학회논문지S
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    • 제36S권12호
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    • pp.107-119
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    • 1999
  • 일반적인 영상에서 얼굴의 위치를 찾아내는 문제는 넓은 응용 영역에도 불구하고 변형의 다양성 때문에 아직도 많은 연구를 필요로 하는 주제이다. 표정, 방향, 회전, 크기, 성별, 나이 등에 따른 얼굴의 변형이 다양하기 때문이다. 이러한 변형을 적절하게 고려하기 위해서 본 논문에서는 특징 요소에 기반을 둔 방법을 사용하였다. 얼굴을 이루는 특징 요소들, 즉, 눈썹, 눈, 코, 입의 배치에 근거해서 얼마나 실제의 얼굴과 비슷한 배치를 이루는 가를 계산하여 얼굴의 위치를 확인한다. 이러한 작업에서는 특징 요소들을 정확히 찾아내는 것이 중요한 문제이다. 본 논문에서는 특징 요소를 정확히 찾기 위하여 일반적인 에지를 찾는 방법대신 크기나 방향을 고려하는 조정 가능한 필터를 사용하였고 특징 요소 기반 방법의 약점을 극복하기 위해서 변형 가능한 템플릿을 사용하여 검증작업을 수행하였다. 또한 기존의 특징 요소 기반 방법을 영상 전체에 대해 적용하면서 검출률이 떨어지는 것을 고려해 본 논문에서는 칼라 영상의 색 정보를 이용하여 작업 영역을 줄이고 검출률을 높이기 위해 변화가 다양한 살색을 찾을 수 있는 분석적인 살색 필터를 구성하였다.

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Reed Switch 센서를 이용한 원격 검침용 상수도 계량기에서 Chattering 오차 감소 방안 연구 (Reduction Chattering Error of Reed Switch Sensor for Remote Measurement of Water Meter)

  • ;권종원;박용만;구상준;김희식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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    • pp.377-379
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    • 2007
  • To reduce the chattering errors of reed switch sensors used for automatic remote measurement of water supply system, a reed switch sensor was analyzed and improved. The operation of reed switch sensors can be described as a mechanical contact by approximation of permanent magnet piece to generate an electrical pulse. The reed switch sensors are used in measurement application by detecting the rotational or translational displacement. To apply for flow measurement devices, the reed switch sensors should keep high reliability. They are applied for the electronic digital type of water flow meters. The reed switch sensor is just installed simply on the mechanical type flow meter. A small magnet is attached on a pointer of the water meter counter rotor. Inside the reed sensor, two steel leaf springs make mechanical contact and apart as rotation of flow meter counter. The counting electrical contact pulses can be converted as the water flow amount. The MCU sends the digital flow rate data to the server using the wireless communication network. But it occurs data difference or errors by chattering noise. The reed switch sensor contains chattering error by it self at the force equivalent position. The vibrations such as passing car near to the switch sensor installed location. In order to reduce chattering error, most system uses just software methods for example using filter and also statistical calibration methods. The chattering errors were reduced by changing leaf spring structure using mechanical hysteresis characteristics.

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수치해석을 이용한 바닥공조 시스템의 공기환경 평가 (Numerical Study on Indoor Air Quality Based on Age of Air for the Underfloor Air Distribution System)

  • 방승기;안혜린;이원근;문기선;김종률;이광호
    • 한국지열·수열에너지학회논문집
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    • 제12권4호
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    • pp.40-46
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    • 2016
  • In order to improve air quality of indoor environment, studies of the underfloor air distribution (UFAD) system for application in buildings are actively in progress based on temperature and air flow distribution. However, although the age of air is the major evaluation parameter, there has been very little study on this parameter for the UFAD system. In this study, we investigated the age of air to reach the air diffuser, which is installed at the bottom of the interior by the UFAD system. Computational fluid dynamics simulations showed no regular pattern to the maximum value of the age of air in accordance with air flow rate and the velocity at air diffuser. These factors can be deduced from air movement by considering that air emitted from air conditioners was rotated according to the bottom shape of the floor, and then, the age of air in the rotation center was increased. The average age of air of internal interior was reduced considerably as the flow velocity at the underfloor air diffuser was increased from 0.5 m/s to 1.0 m/s However, the age of air was not substantially affected with change in the air volume. Moreover, when the flow velocity at the underfloor air diffuser was higher than 1.0 m/s, the age of air showed no significant difference with change in air volume or height of measurement. These results imply that indoor air quality is more substantially influenced by flow velocity than air volume, and the appropriate flow velocity is 1 m/s or more.

저낙차에서 와류발생부를 구비한 마이크로 소수력에 관한 실험 연구 (Experimental Study of Micro hydropower with Vortex Generation at Lower Head Water)

  • 최인호;김종우;정기수
    • 한국습지학회지
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    • 제22권2호
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    • pp.121-129
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    • 2020
  • 본 논문은 자유수면을 가지는 와류유동 내 저낙차에서 마이크로 소수력에 관한 실험 연구이다. 내부 곡선 모서리가 있는 직선, 곡선, 비틀린 블레이드의 와류 높이, 터빈 회전 및 토크를 개수로 유입구의 유량 0.0069 ㎥/s 조건에서 측정하였다. 실험결과로서 최적의 와류 강도는 와류 발생부의 외부직경과 유출구 직경 비율 0.17~18.5 범위에서 발생했다. 직선 블레이드 출력과 효율은 다른 블레이드와 비교하여 높게 나타났다. 가장 높게 생성된 에너지는 12.33 W이고, 토크는 0.91 N·m이다. 유효낙차를 고려한 경우 가장 높은 효율은 29.5 %인 반면 와류 높이를 고려한 가장 높은 효율은 회전수 132 rpm에서 80.5 %이다. 직선 블레이드의 와류 유속은 개수로 유입구의 평균 유속보다 약 2.8배 더 크게 나타난다.

연골세포와 중간엽줄기세포의 3차원 Co-culture를 통한 연골화 향상 (Enhanced Chondrogenesis by Three-dimensional Co-culture of Chondrocytes and Mesenchymal Stem Cells)

  • 황슬기;차현명;임진혁;이지희;심혜은;김동일
    • KSBB Journal
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    • 제31권2호
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    • pp.120-125
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    • 2016
  • Two-dimensional cultivation is typically used for cell growth, but the method reduces the characteristics of chondrocytes and stem cells, and limits culture area. Therefore, development of three-dimensional culture method is needed to mimic in vivo environment, improve quality of cells and scale-up efficiently. Improving proliferation and chondrogenesis is available by co-culture of chondrocytes and mesenchymal stem cells (MSCs) that leads to interaction between two kinds of cells. However, the co-culture has problems that permeability of sphere diminishes as aggregate size increased and ratio of two kinds of cells composing each spheres is different. In this work, co-cultivation method using controlled sphere composed of chondrocytes and MSCs was established and enhanced chondrogenesis. Periosteum-derived progenitor cells (PDPCs) that are appropriate for cell therapy source of articular cartilage were used as MSCs. Controlled spheres were formed in the hanging-drop plates and shifted for being induced chondrogenesis in 35-mm non-adhesive culture dishes at a rotation rate of 60 rpm. After inducing chondrogenesis, gene expressions related with chondrogenesis were found to be improved and it was apparent that the utilization of controlled spheres promoted chondrogenesis. As a result, available numbers of cells per unit area were increased and chondrogenic differentiation ability was improved compared to typical two-dimensional culture. This approach shows the potential in cartilage regeneration as it can provide sufficient numbers of chondrocytes.

황백나무로부터 항균성분의 분리 및 정제 (Isolation and Purification of Antibacterial Components in Cortex Phellodendri)

  • 김중배;신운섭;권영인;방병호
    • 한국식품영양학회지
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    • 제26권3호
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    • pp.547-552
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    • 2013
  • 황백 껍질은 황벽나무(Phellodendron amurense)의 건조된 수피로부터 얻어진다. 이 수피는 한국의 전통 한약제로서, 설사, 황달, 무릎과 발의 통증, 요도관 및 피부 감염증에 폭넓게 사용되어 왔다. 본 연구는 황벽나무의 메탄올 추출액으로부터 항균성 화합물 분리를 위해 CPC 방법으로 효과적으로 수행하였다. 두 용매의 CPC 최적조성은 n-butanol:acetic acid:water(4:1:5 v/v/v)이었다. 이동상의 유속은 1,000 rpm 회전력에서 상승법으로 분당 3 $m{\ell}$ 속도로 전개시켰다. CPC에서 분리된 분획분은 prep-HPLC로 정제하였다. 분리된 palmatine은 $^1H$, $^{13}C$-NMR, ESI-MS 데이터 분석으로 확인하였다.

덕트의 유로 최적화를 통한 소음저감 연구 (Study on Noise Reduction by Optimizations of In-line Duct Flow)

  • 한재오;이수영;모진용;이재권
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.803-808
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    • 2006
  • This paper was a study about noise reduction through flow stabilization in duel using experimental method and numerical analysis at the same time. To determine the fan's type three kinds of fans(axial fan, centrifugal fan, and axial fan with centrifugal type) was examined to investigate the suitability for duct. As a result, under the equal number of rotation 2000 RPM, performance of an axial fan with centrifugal type was the most superior by 55dBA at 4.3CMM among other fans. After this, analyzed the results of the numerical analysis to find out the optimum design of pitch angle such as $0^{\circ},\;10^{\circ},\;15^{\circ}\;and\;20^{\circ}$. The intensity of turbulence was low when pitch angle was $15^{\circ}$ and air volume became peak by 5.08 CMM. It was observed that axis component of velocity increased gradually when pitch angle increased from $0^{\circ}\;to\;20^{\circ}$. Finally, designed the shapes of D/S(Down Stream) in duct that agreed inlet angle($\delta$) of stationary blades with pitch angle($\beta$) of axial fan with centrifugal type and derived flow to duct medial, and changed the shape of motor-mount to reduce occurance of unstable vortex in tip of impeller, and embodied noise reduction and improvement of air flow rate through flow stabilization.

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수평자장 하에서 성장된 CZ 실리콘 단결정의 산소 분포 및 석출거동 (Oxygen Profiles and Precipitation Behavior in CZ Silicon Crystals Grown in A Transverse Magnetic Field)

  • 김경민;최광수;;;이문희
    • 한국재료학회지
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    • 제2권2호
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    • pp.119-125
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    • 1992
  • 수평자장을 건 Czochralski(HMCZ) 방법으로 자장강도(B)와 도가니 회전속도(C)가 실리콘 단결정의 산소편석에 미치는 영향에 대하여 연구하였다. B=2, 3, 4kG와 C=4-15rpm에서 <100> 방향으로 성장시킨 57mm 직경의 단결정들 내의 산소분포는 대체로 축을 따라서 불균일하였고 톱니모양을 나타내었다. 종래의 CZ 방법과 비교할 때, 이러한 산소분포의 불균일성은 위 강도의 수평자장이 결정성장계면으로의 산소전달에 불안정한 요소로 작용했음을 나타낸다고 볼 수 있다. 반면에 C의 증가는 산소분포의 불균일성의 약화와 산소농도의 전반적인 증가를 유도하였다. 이 결과를 토대로 B=2kG에서 27-36ppma인 산소분포를 가진 단결정이 프로그램된 C에 의해서 얻어졌다. 소자제조공정을 모의한 열처리 과정에서 HMCZ 실리콘의 산소석출은 종래의 CZ 실리콘의 산소석출에 비해서 상대적으로 불균일하였고, as-grown 상태에서의 고르지 못한 HMCZ 실리콘의 산소분포가 주요 원인임이 밝혀졌다.

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Effectiveness of the Anti-adhesive Agent Protescal after Arthroscopic Rotator Cuff Repair: A Retrospective Study

  • Chung, Pill Ku;Yoo, Jae Chul;Jeong, Jeung Yeol
    • Clinics in Shoulder and Elbow
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    • 제20권1호
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    • pp.3-9
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    • 2017
  • Background: Many hyaluronic acid (HA)-based anti-adhesive agents have been commercialized for clinical use in the pharmaceutical market. But their efficacy in arthroscopic rotator cuff repairs remains elusive. To determine their efficacy, we performed a comparative analysis of the effects of two hyaluronate/carboxymethylcellulose (CMC)-based anti-adhesive agents, Protescal and Guardix. Methods: We recruited a total of 256 patients who had received an arthroscopic rotator cuff repair at our hospital between January 2014 and March 2015. Among them, 96 patients fulfilled the study's selection criteria and were enrolled as the final population sample. Thirty patients who had received a postoperative injection of Protescal were allocated into Group A. Another 30 patients who had received a postoperative injection of Guardix were allocated into Group B. As controls, 36 patients who did not receive any injection were allocated into Group C. The patients included in this study were aged between 19 and 75 years. For the clinical assessment, we measured the following clinical parameters-the visual analogue scale for pain (PVAS), the American Shoulder and Elbow Surgeons (ASES) score, and the constant score, as well as passive range of motions (ROMs)-at three time-points (preoperatively, 2-month postoperatively, and 6-month postoperatively). Results: We found that Group A compared to Group B tended to show a swifter recovery in passive anterior elevation and in internal rotation by the 2-month postoperative follow-up, but the differences were not statistically significant. Conclusions: We found that the effects of HA/CMC-based injections were minimal after arthroscopic rotator cuff repairs.

용출형 극세사와 저온 융착사를 이용한 인테리어 직물의 가공 (Finishing of Interior Fabric Using Soluble Micro-fiber and low melting Yarn)

  • 안영무
    • 패션비즈니스
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    • 제13권2호
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    • pp.78-86
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    • 2009
  • When scouring and contraction finishing at $90^{\circ}C$ using Relaxer or Rotary Washer contraction and weight loss ratio in warp and weft directions were excellent. Also surface state of fabric after drying or sanding treatment was excellent without crease. Low melting polyester fabric showed a complete melting bond by heat setting(P/S) at above $160^{\circ}C$. The alkali hydrolysis reaction of polyester showed the breakpoint in the weight loss behavior test, polyester yarn showed a breakpoint ranging from 25% to 28%. This is due to the difference of the hydrolysis rate between regular polyester and soluble polyester. Initially the soluble polyester was eluted and micro-fibrillized 5 times faster than a regular polyester. At a later time, a regular polyester was reduced weight to impart a proper flexibility and drape property to the fabric. As a result of surface sanding finishing, the surface of interior fabric showed a surface state most stabilized when using Mesh No. 220 in mono 0.2d after elution finishing. When the rotation direction of sanding roller was pro-, pro-, pro-, and retro-direction, a directional effect of tuft was not shown, a writing effect as suede was exhibited and a surface state was even. Sublimation fastness was 3-4 class for polyester and 2-4 class for nylon. Light fastness 3-4 class after lapse of 100 hours and 2-4 class after lapse of 160 hours. Abrasion fastness was 3-4 class on wet and 4-5 class on dry Laundry fastness was 2-4 class. As such, the abrasion fastness is slightly reduced upon wetting and the use thereof for interior is excellent, whereas laundry fastness is slightly lowered.