• 제목/요약/키워드: Smooth area

검색결과 468건 처리시간 0.034초

Grid Discretization Study for the Efficient Aerodynamic Analysis of the Very Light Aircraft (VLA) Configuration

  • Sitio, Moses;Kim, Sangho;Lee, Jaewoo
    • International Journal of Aeronautical and Space Sciences
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    • 제14권2호
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    • pp.122-132
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    • 2013
  • In this research the development of unstructured grid discretization solution techniques is presented. The purpose is to describe such a conservative discretization scheme applied for experimental validation work. The objective of this paper is to better establish the effects of mesh generation techniques on velocity fields and particle deposition patterns to determine the optimal aerodynamic characteristics. In order to achieve the objective, the mesh surface discretization approaches used the VLA prototype manufacturing tolerance zone of the outer surface. There were 3 schemes for this discretization study implementation. They are solver validation, grid convergence study and surface tolerance study. A solver validation work was implemented for the simple 2D and 3D model to get the optimum solver for the VLA model. A grid convergence study was also conducted with a different growth factor and cell spacing, the amount of mesh can be controlled. With several amount of mesh we can get the converged amount of mesh compared to experimental data. The density around surface model can be calculated by controlling the number of element in every important and sensitive surface area of the model. The solver validation work result provided the optimum solver to employ in the VLA model analysis calculation. The convergence study approach result indicated that the aerodynamic trend characteristic was captured smooth enough compared with the experimental data. During the surface tolerance scheme, it could catch the aerodynamics data of the experiment data. The discretization studies made the validation work more efficient way to achieve the purpose of this paper.

두피 및 사지에 다발성 섬유종을 동반한 결절성 경화증 (A Case of Tuberous Sclerosis with Multiple Fibroma on Scalp and Extremity)

  • 김형석;정희선;신극선;이상엽;송지선
    • Archives of Plastic Surgery
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    • 제35권3호
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    • pp.341-344
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    • 2008
  • Purpose: Tuberous sclerosis is an autosomal dominant multisystemic neurocutaneous syndrome characterized by the development of multiple hamartoma distributed through the body, skin, brain, heart, kidney, and lung. The classic triad is seizure, mental retardation, and facial angiofibroma. We experienced a case of a tuberous sclerosis associated with the facial lesion and multiple masses on scalp, forehead, and right lower extremity. Methods: This a 34-year-old male patient had subependymal giant cell astrocytoma in brain and multiple angiomyolipoma in both kidneys. Tangential excision with razor blade and dermabrasion were done on the centrofacial area. We excised other lesions and the mass on scalp was excised and covered with split thickness skin graft. Results: The histopathological finding revealed that the facial lesion was angiofibroma and the others were multiple fibroma. Conclusion: In our case of tuberous sclerosis, we chose the tangential excision to remove the large nodules of angiofibroma, and then dermabrasion was used to smooth the final contour. The patient appeared to have a good results from this treatment modality. But, tuberous sclerosis is an disease that needs long term follow-up to check up the recurrence of skin problem.

위 내 이물로 오인한 석회화 섬유 종양 1예 (Calcifying Fibrous Tumor Mimicking a Foreign Body of the Stomach: A Case Report)

  • 정지은;이경훈;성현정;조창호
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제12권1호
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    • pp.57-63
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    • 2009
  • 평소 복부 팽만을 보인 2세 남아가 내원 3일 전부터 간헐적인 구토를 동반하여 시행한 복부 방사선 사진에서 좌상복부에서 석회화 소견을 관찰하여 상부 위장관내시경과 복부 전산화 단층 사진을 시행하였다. 술 후 병리 검사에서 상당히 빈도가 드문 석회화 섬유 종양을 발견하였기에 보고하는 바이다.

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Occurrence of Rhizopus Soft Rot on Peach (Prunus persica var. vulgaris) Caused by Rhizopus nigricans in Korea

  • Kwon, Jin-Hyeuk;Kang, Soo-Woong;Park, Chang-Seuk
    • Mycobiology
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    • 제28권4호
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    • pp.177-179
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    • 2000
  • A soft rot of fruits caused by Rhizopus nigricans occurred on peach (Prunus persica var. vulgaris) in The Chinju City Agricultural Products Wholesale Marke during in summer season of 2000. The disease infection usually started from wounding after harvest fruits, and then moved to outside. At first, the lesions started with water soaked and rapidly softened and diseased area gradually expanded. In severely infected film house, the rate of infected fruits reached 65.2%. Numerous sporangiospores were produced on the diseased fruits. Most of the sporangiospores were appeared to be readily dispersed in the air. The mycelia grew surface of fruits and produced stolons. Colonies on potato dextrose agar at $25{\sim}30^{\circ}C$ white cottony at first becoming heavily speckled by the presence of sporangia and the browinish black at maturity, spreading rapidly by means of stolons fired at various points to the substrate by rhizoids. Sporangia were $85.3{\sim}243.5{\times}53.4{\sim}219.2\;{\mu}m$ in size and were globose or sub-globose with. somewhat flattened base. The color of sporangia was white at first and then turned black with many spores, and never over-hanging. Sporangiophores were $8.9{\sim}36.6\;{\mu}m$ in width, smooth-walled, non-septate, light brown, simple, long, arising in groups of $3{\sim}5$ from stolons opposite rhizoids. Sporangiospores was $9.7{\sim}24.8{\times}5.9{\sim}15.8\;{\mu}m$, irregular, round, oval, elongate, angular, and browinish-black streaked. Columella was $70.2{\times}149.7{\mu}m$. brownish gray, and umberella-shaped when dehisced. The causal organism was identified as. Rhizopus nigricans Lind on the basis of the morphiogical characteristics of the fungus. Rhizopus soft rot on peach (Prunus persica) caused by the fungi has not been reported in Korea. This is the first report of rhizopus soft rot on peach caused by Rhizopus nigricans in Korea.

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Identification of country of production of veal meat by NIRS and by meat quality measurements.

  • Berzaghi, Paolo;Serva, Lorenzo;Gottardo, Flaviana;Cozzi, Giulio;Andrighetto, Igino
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1255-1255
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    • 2001
  • The study used 356 veal calf meat samples received from Finland (n=16), France (n=109), Italy (n=81) and The Netherlands (n=150). Calves were raised under experimental protocols that compared feeding and housing practices normally used in each county to treatments aiming at improving animal welfare. Samples were taken at the $8^{th}$ rib of Longissimus thoracis muscle 24h after slaughter, They were kept refrigerated ( $2-4^{\circ}C$) under vacuum package for 6d and then frozen ($-20^{\circ}C$) until meat quality evaluation. Measurements included pH, color (Hunter Lab system), shear force, chemical composition (DM, Ash, Ether Extract, collagen and haematin content), weight and area cooking losses and a sensory evaluation by a group of panelists. A sample of meat was ground with a blade mill and scanned in duplicate between 1100 and 1498 nm (FOSS NIR Systems 5000). WinISI software was used to develop a discriminating equation using NIR spectra (SNV-detrend, derivative=1, gap=4nm, smooth=4nm). The Proc ANOVA and DISCRIM of SAS were used for all the laboratory determinations. County of production had a significant (P<0.01) effect on all the parameters. However, discriminant analysis using any or few laboratory parameters resulted in great errors of county classification. A more accurate (98.8%) classification was obtained only when using all the laboratory parameters. NIRS classified correctly 354 of the 356 samples (99.4%). Provided with a larger data set, NIRS could be used to identify country of production of veal meat.

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컴퓨터 시각 인식 기법을 이용한 영상 중첩법에 의한 개인식별 (Image Superimposition for the Individual Identification Using Computer Vision System)

  • Ha-Jin Kim
    • Journal of Oral Medicine and Pain
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    • 제21권1호
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    • pp.37-54
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    • 1996
  • In this thesis, a new superimposition scheme using a computer vision system was proposed with 7 pairs of skull and ante-mortem photographs, which were already identified through other tests and DNA fingerprints at the Korea National Institute of Scientific Investigation. At this computer vision system, an unidentified skull was caught by video-camcoder with the MPEG and a ante-mortem photograph was scanned by scanner. These two images were processed and superimposed using pixel processing. Recognition of the individual identification by anatomical references was performed on the two superimposed images. These results were as followings. 1. For the enhancement of skull and ante-mortem photographs, various image processing schemes, such as SMOOTH, SHARPEN, EMBOSS, MOSAIC, ENGRAVE, INVERT, NEON and COLOR TO MONO, were applied using 3*5 window processing. As an image processing result of these methods, the optimal techniques were NEON, INVERT and ENGRAVE for the edge detection of skull and ante-mortem photograph. 2. Using various superimposition image processing techniques (SRCOR, SRCAND, SRCINVERT, SRCERASE, DSTINVERT, MERGEPAINT) were compared for the enhancement of image recognition. 3. By means of the video camera, the skull image was inputed directly to a computer system : superimposing it on the ante-mortem photograph made the identification more precise and time-saving. As mentioned above, this image processing techniques for the superimposition of skull and ante-mortem photographs simply used the previous approach, In other wrods, taking skull photographs and developing it to the same size as the ante-mortem photographs. This system using various image processing techniques on computer screen, a more precise and time-saving superimposition technique could be able to be applied in the area of individual identification in forensic practice.

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금속유기분해법으로 제조한 니켈 망가나이트 박막의 구조적 특성 (Structural Properties of Nickel Manganite Thin Films Fabricated by Metal Organic Decomposition)

  • 이귀웅;전창준;정영훈;윤지선;남중희;조정호;백종후;윤종원
    • 한국전기전자재료학회논문지
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    • 제27권4호
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    • pp.226-231
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    • 2014
  • Thin thermistor films of solutions with nickel and manganese oxides were prepared by metal-organic decomposition (MOD). The structural properties of the thin films were investigated as a function of annealing temperature. Field emission scanning electron microscope (FE-SEM) results indicated that the thin films had a thin thickness, smooth and dense surface. The crystallization temperature of $414.9^{\circ}C$ was confirmed from thermogavimetric-differential thermal analysis (TG-DTA) curve. A single phase of cubic spinel structure was obtained for the thin film annealed from $700^{\circ}C$ to $800^{\circ}C$, which was confirmed from the X-ray diffraction (XRD). From the selected area electron diffraction (SAED) in high resolution transmission electron microscope (HRTEM), the nano grains (2~3 nm) of spinel phase with (311) and (222) planes were detected for the thin film annealed at $500^{\circ}C$, which could be applicable to read-out integrated circuit (ROIC) substrate of the uncooled microbolometer with low processing temperature.

여러 가지 형태의 립이 설치된 수평채널의 열전달 및 압력강하 특성에 관한 수치해석 (Numerical analysis on heat transfer and pressure drop characteristics in a horizontal channel with various ribs)

  • 김지훈;허주녕;안성후;이두호;손영석;신지영
    • Journal of Advanced Marine Engineering and Technology
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    • 제37권1호
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    • pp.40-46
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    • 2013
  • 열전달 향상을 위하여 이차유동을 발생시켜 열전달을 증가시키는 방법에는 여러 가지가 있다. 본 연구에서는 수평채널에 다양한 형태의 립을 설치하여 유속을 변화시켰을 때의 열전달 및 압력강하 특성을 수치해석을 통하여 고찰하였다. 립은 수평채널의 아랫면에 설치하였고, 립의 높이는 5mm이다. 립이 $60^{\circ}$ 기울어지고 그루브도 설치된 경우 열전달 특성이 가장 우수하게 나타났는데, 이는 주유동이 립을 따라 흘러가면서도 유속이 어느 정도 유지되기 때문이다. 끊어진 립에서 주유동이 립의 저항을 적게 받으면서 압력강하가 가장 작게 나타났다. 모든 립의 형태에서 유속이 증가함에 따라 열전달이 향상되는 경향을 보였지만 성능계수는 감소하였다.

원자력 시설 주변 지역주민의 원자력에 대한 인식 조사 (Investigation of Perception of Nuclear Power by the Local Residents Adjacent to Nuclear Installations)

  • 조경영;문주현
    • 방사성폐기물학회지
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    • 제9권3호
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    • pp.181-189
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    • 2011
  • 원자력시설의 원활한 건설 운영을 위해서는 해당 지역주민뿐만 아니라 일반 국민의 이해와 지지가 필요하다. 국가 에너지 안보와 경제성장을 위해 원자력을 지속 이용해야 하는 우리나라는 원자력의 사회적 수용성을 증진시키는 것이 중요하다. 원자력에 대한 사회적 수용성 수준을 파악하기 위해, 본 연구에서는 원자력발전소와 중 저준위 방사성폐기물처분장이 동시에 입지해 있는 경주 지역주민과 기타 지역주민의 원자력에 대한 인식을 설문 조사하였다. 설문조사는 총 450명을 대상으로 개별면접을 통해 이루어졌다. 본 설문조사를 통해 거주 지역에 따라 원자력시설에 대한 인식이 다소 다르다는 것을 확인할 수 있었으며, 지역별, 연령별 맞춤형 홍보 전략을 수립하는데 반영해야 할 시사점도 도출하였다.

Characterization of $ET_B$ Receptor-mediated Relaxation in Precontracted Mesenteric Artery from Streptozotocin-induced Diabetic Rats

  • Eom, Yang-Ki;Kim, Koan-Hoi;Rhim, Byung-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • 제9권5호
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    • pp.305-314
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    • 2005
  • Diabetes mellitus is associated with vascular complications, including an impairment of vascular function and alterations in the reactivity of blood vessels to vasoactive substances in various vasculature. In the present study, the authors have observed endothelin-B ($ET_B$) receptor agonist-induced relaxation in precontracted mesenteric arterial segments from streptozotocin (STZ)-induced diabetic rats, which was not shown from control rats or in other arterial segments from diabetic rats. Accordingly, the goal of this study was to investigate in what way STZ-induced diabetes altered reactivity of the mesenteric arterial bed and to examine the causal relaxation, if any, between this $ET_B$ receptor-mediated relaxation and endothelial paracrine function, especially nitric oxide (NO) production. The relaxation induced by $ET_B$ agonists was not observed in mesenteric arteries without endothelium. The relaxation to $ET_B$ agonists was completely abolished by pretreatment with BQ788, but not by BQ610. $N_{\omega}-nitro-L-arginine$ methyl ester and soluble guanylate cyclase inhibitors, methylene blue or LY83583 significantly attenuated the relaxant responses to $ET_B$ agonists, respectively. When the expression of eNOS and iNOS was evaluated on agarose gel stained with ethidium bromide, the expression of eNOS mRNA in diabetic rats was significantly decreased, but the expression of iNOS was increased compared with control rats. Furthermore, the iNOS-like immunostaining was densely detected in the endothelium and slightly in the arterial smooth muscle of diabetic rats, but not in control rats. These observations suggest that $ET_B$ receptor may not play a role in maintaining mesenteric vascular tone in normal situation. However, the alterations in $ET_B$ receptor sensitivity were found in diabetic rats and lead to the $ET_B$ agonist-induced vasorelaxation, which is closely related to NO production. In the state of increased vascular resistance of diabetic mesenteric vascular bed, enhanced NO production by activation of iNOS could lead to compensatory vasorelaxation to modulate adequate perfusion pressure to splanchnic area.