• Title/Summary/Keyword: Synthetic

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Separation control using multi-array/multi-location synthetic jet (Multi-array/multi-location synthetic jet을 이용한 박리 제어)

  • 김상훈;김종암
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.8
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    • pp.8-15
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    • 2006
  • Separation control has been performed using the multi-array/multi-location synthetic jet on NACA23012 at high angle of attack. The flow control using single synthetic jet shows that stall characteristics can be substantially improved with delayed separation point. Theses results show the characteristic of unsteady flow of single synthetic jet. Beside, we researched on multi-array synthetic jet to obtain applicable synthetic jet velocity. Multi-location synthetic jet is proposed to eliminate small vortex on suction surface of airfoil. With the results, we concluded that the flow around airfoil is stable by high frequency synthetic jet with elimination of small vortex and confirmation of stable flow. Moreover, performance of multi-array/multi-location synthetic jet can be improved by changing phase angle of multi-location synthetic jet.

SEPARATION CONTROL MECHANISM USING SYNTHETIC JET ON AIRFOIL (익형에서의 synthetic jet을 이용한 박리제어 mechanism)

  • Kim, S.H.;Kim, W.;Hong, W.;Kim, C.
    • 한국전산유체공학회:학술대회논문집
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    • 2007.10a
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    • pp.60-66
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    • 2007
  • Separation control has been performed using synthetic jets on airfoil at high angle of attack. Computed results demonstrated that stall characteristics and control surface performance could be substantially improved by resizing separation vortices. It was observed that the actual flow control mechanism and flow structure is fundamentally different depending on the range of synthetic jet frequency. For low frequency range, small vortices due to synthetic jet penetrated to the large leading edge separation vortex, and as a result, the size of the leading edge vortex was remarkably reduced. For high frequency range, however, small vortex did not grow up enough to penetrate into the leading edge separation vortex. Instead, synthetic jet firmly attached the local flow and influenced the circulation of the virtual airfoil shape which is the combined shape of the main airfoil with the separation vortex. Theses results show the characteristic of unsteady flow of single synthetic jet. Beside, we researched on multi-array synthetic jet to obtain applicable synthetic jet velocity. Multi-location synthetic jet is proposed to eliminate small vortex on suction surface of airfoil. With the results, we concluded that the flow around airfoil is stable by high frequency synthetic jet with elimination of small vortex and confirmation of stable flow. Moreover, performance of multi-array/multi-location synthetic jet can be improved by changing phase angle of multi-location synthetic jet.

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SEPARATION CONTROL USING SYNTHETIC JET ON NACA23012 AT HIGH ANGLE OF ATTACK (고받음각의 NACA23012익형에서 synthetic jet을 이용한 박리 제어 연구)

  • Kim S. H.;Kim C.;Kim K. H.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.125-129
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    • 2005
  • Flow control has been performed using synthetic jet on NACA23012. In order to improve aerodynamic performance, synthetic jet is located near separation paint on airfoil with leading edge droop and plain flap. The flow control using synthetic jet shows that stall characteristics and control surface performance can be improved through resizing separation vortices. Stall is delayed and stall characteristics are improved when synthetic jet is applied from separation region of leading edge droop. Control surface effectiveness is increased and lift is increased when synthetic jet applied at the flap leading edge region. The results show that aerodynamic characteristics can be improved through leading edge droop with synthetic jet at near separation and plain flap with synthetic jet at the flap leading edge. The combination of synthetic jet and simple high lift device is as good as fowler flap system.

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A study on the crack characteristics of the Synthetic Fiber reinforced Soil (섬유 보강토의 균열 특성 연구)

  • 송창섭;이신호;반창현;인현식
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 1998.10a
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    • pp.431-437
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    • 1998
  • This study was performed to ascertain the three-dimensional effect of the crack reduction and the restrained effect of crack growth, and to yield a suitable mixing ratio of the synthetic fiber reinforced soil. The results of the study are as follows ; 1) The synthetic fiber has the resisting force for crack because of the adhesion due to the attraction of soil particles. 2) As the synthetic fiber length and the mixing ratio are increased, mono filament synthetic fiber reinforced soil is increased the effects of crack reduction and the restraint of crack growth. 3) The fibrillated synthetic fiber is more effective than mono filament synthetic fiber for crack. 4) A suitable mixing ratio of synthetic fiber reinforced soil is 0.5% of the fibrillated synthetic fiber.

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Economic Design of Synthetic Control Charts (합성 관리도의 경제적 설계)

  • 임태진;김용덕
    • Journal of Korean Society for Quality Management
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    • v.31 no.2
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    • pp.117-130
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    • 2003
  • This paper investigates the economic design of synthetic control charts. The synthetic control chart has been proven to be statistically superior to the $\bar{X}$-control chart, but its economic characteristics have not been known. We develop an economic model of the synthetic control chart, based on Duncan's model. The synthetic chart has one more decision variable, the lower control limit for the conforming run length. In addition to this, the significance level and the power of the synthetic chart are more complicated than those of the $\bar{X}$-chart. These features make the optimization problem more difficult. We propose an optimization algorithm by adapting the congruent gradient algorithm. We compare the optimal cost of the synthetic chart with that of (equation omitted)-control chart, under the same input parameter set of Duncan’s. For all cases investigated, the synthetic chart shows superior to the $\bar{X}$-chart. The synthetic control chart is easy to implement, and it has better characteristics than the $\bar{X}$-chart in economical sense as well as in statistical sense, so it will be a good alternative to the traditional control charts.

Flow control using synthetic jet on NACA23012 (NACA23012익형에서 synthetic jet을 이용한 유동 제어)

  • 김상훈;김종암
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.6
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    • pp.10-17
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    • 2006
  • NACA23012익형에 대하여 synthetic jet을 이용하여 박리 제어를 수행하였다. 공력특성의 향상을 위해 앞전 droop과 plain flap의 박리 부근에 synthetic jet을 위치시켰다. 고 받음각에서 앞전 박리의 발생으로 인한 실속을 앞전 droop의 작동과 이때 발생하는 앞전 박리를 synthetic jet으로 효과적으로 지연시킬 수 있고, 또한 실속 특성을 개선 할 수 있음을 확인하였다. 양력의 향상을 위하여 plain flap을 장착하였고, 이때 발생하는 박리를 synthetic jet으로 지연시켜 제어면의 작동 효율을 증가 시킬 수 있음을 확인하였다. 앞전 droop과 plain flap으로 구성된 간단한 고양력 장치에 발생하는 박리를 synthetic jet으로 제어함으로 실속을 지연시킴과 동시에 실속 특성을 향상시키고, 최대 양력의 증가로 fowler flap에 버금가는 공력특성을 확보할 수 있음을 확인하였다.

Novel High-Throughput DNA Part Characterization Technique for Synthetic Biology

  • Bak, Seong-Kun;Seong, Wonjae;Rha, Eugene;Lee, Hyewon;Kim, Seong Keun;Kwon, Kil Koang;Kim, Haseong;Lee, Seung-Goo
    • Journal of Microbiology and Biotechnology
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    • v.32 no.8
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    • pp.1026-1033
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    • 2022
  • This study presents a novel DNA part characterization technique that increases throughput by combinatorial DNA part assembly, solid plate-based quantitative fluorescence assay for phenotyping, and barcode tagging-based long-read sequencing for genotyping. We confirmed that the fluorescence intensities of colonies on plates were comparable to fluorescence at the single-cell level from a high-end, flow-cytometry device and developed a high-throughput image analysis pipeline. The barcode tagging-based long-read sequencing technique enabled rapid identification of all DNA parts and their combinations with a single sequencing experiment. Using our techniques, forty-four DNA parts (21 promoters and 23 RBSs) were successfully characterized in 72 h without any automated equipment. We anticipate that this high-throughput and easy-to-use part characterization technique will contribute to increasing part diversity and be useful for building genetic circuits and metabolic pathways in synthetic biology.

Perception Ability of Synthetic Vowels in Cochlear Implanted Children (모음의 포먼트 변형에 따른 인공와우 이식 아동의 청각적 인지변화)

  • Huh, Myung-Jin
    • MALSORI
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    • no.64
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    • pp.1-14
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    • 2007
  • The purpose of this study was to examine the acoustic perception different by formants change for profoundly hearing impaired children with cochlear implants. The subjects were 10 children after 15 months of experience with the implant and mean of their chronological age was 8.4 years and Standard deviation was 2.9 years. The ability of auditory perception was assessed using acoustic-synthetic vowels. The acoustic-synthetic vowel was combined with F1, F2, and F3 into a vowel and produced 42 synthetic sound, using Speech GUI(Graphic User Interface) program. The data was deal with clustering analysis and on-line analytical processing for perception ability of acoustic synthetic vowel. The results showed that auditory perception scores of acoustic-synthetic vowels for cochlear implanted children were increased in F2 synthetic vowels compaire to those of F1. And it was found that they perceived the differences of vowels in terms of distance rates between F1 and F2 in specific vowel.

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A Study on the Crack Characteristics of the Syntetic Fiber Reinforced Soil (섬유 보강토의 균열 특성 연구)

  • 송창섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.3
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    • pp.59-65
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    • 1999
  • This study has been performed to confirm the three dimensional effect of the crack reduction and the restrained effect of crack growth for the synthetic fiber reinforced soil. Two types of polyrpropylene fiber and low plastic clay(CL) were used for the test. And the test variable were fiber length and so on. The results of the study were summarized as follows ; 1) The mixing of synthetic fiber was effective in reducing crack growth due to adhesion between soil partlcles and synthetic fiber.l Especially initlal crack was delayed, as compared with the pure soil, for about 1 day in case of mono filament synthetic fiber and for about 1 or 2 days in case of fibrillated syntetic fiber. 2) As the content and length of synthetic fiber were increased , the effect of crack reduction was increased. It was found that 0.5% fibrillated synthetic fiber with 40mm length reinforced soil had about 3 times more effective than natural soils. 3) In case of the same fiber content and fiber length, the fibrillated synthetic fiber has nmore effective than the mono filament synthetic fiber for crack reduction.

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Synthetic Bacteria for Therapeutics

  • Lam VO, Phuong N.;Lee, Hyang-Mi;Na, Dokyun
    • Journal of Microbiology and Biotechnology
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    • v.29 no.6
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    • pp.845-855
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    • 2019
  • Synthetic biology builds programmed biological systems for a wide range of purposes such as improving human health, remedying the environment, and boosting the production of valuable chemical substances. In recent years, the rapid development of synthetic biology has enabled synthetic bacterium-based diagnoses and therapeutics superior to traditional methodologies by engaging bacterial sensing of and response to environmental signals inherent in these complex biological systems. Biosynthetic systems have opened a new avenue of disease diagnosis and treatment. In this review, we introduce designed synthetic bacterial systems acting as living therapeutics in the diagnosis and treatment of several diseases. We also discuss the safety and robustness of genetically modified synthetic bacteria inside the human body.